Missive vs Fastmail

Multi account

1. switcherConnect several accounts across providers — Gmail, Microsoft 365, IMAP — and work them from one place

   weight 3 · round to Fastmail
   Missive~partialclaimed4/10

   Evidence only touches this obliquely: contacts management explicitly 'syncs with Office 365 and Google' (missive-docs-23), and shared/team inboxes are documented (missive-docs-32, missive-docs-28), implying multi-account consolidation, but there is no explicit documentation in the pack of connecting Gmail, Microsoft 365, and generic IMAP accounts as email sources worked from one unified inbox. Missing for 10: explicit account-connection docs for Gmail/O365/IMAP email (not just contacts sync), and confirmation that all provider types can be combined in one inbox view.

   • [claimed-docs] “Manage your contacts in shared or private address books. ✓ Syncs with Office 365 and Googl”
   • [claimed-docs] “From distribution lists to shared inboxes”
   • [claimed-docs] “Have multiple people work out of the same inbox, without stepping on each other’s toes.”

   proof ↗⚑ flag

   Fastmail~partialcommunity6/10

   Fastmail explicitly documents importing mail from other providers and 'fetching mail from Gmail like a mail client' (IMAP-style pull), plus a 'Logging in to multiple accounts' feature and a dedicated Gmail-migration guide, and community reports confirm smooth Gmail-to-Fastmail migrations. However, evidence never mentions Microsoft 365/Exchange connectivity specifically, doesn't show a true unified single-inbox view merging external accounts (vs. separate logins), and one commenter notes migrating filters/rules doesn't come over cleanly. Missing for 10: explicit Microsoft 365/M365 account linking, detail on whether multiple accounts appear merged in one inbox view, and independent verification of multi-provider IMAP account aggregation beyond Gmail.

   • [community] “As an alternative to forwarding, you can also configure Fastmail to fetch mail from (and send via) Gmail like a mail client.”
   • [community] “Fastmail has an easy migration tool as well if you don't want to go the IMAP route. Now, migrating filters and rules over on the other hand.…”
   • [claimed-docs] “Import your mail”
   • [claimed-docs] “Logging in to multiple accounts”
   • [claimed-docs] “Move from Gmail”

   proof ↗⚑ flag

Portability

1. switcherMy mail stays reachable over open protocols and standard formats — IMAP/JMAP/SMTP access and standards-based export — so no client can lock me in

   weight 2 · round to Fastmail
   Missive—none0/10

   The evidence pack contains no mention of IMAP, JMAP, or SMTP access for user mailboxes, nor any standards-based export functionality; all connectivity evidence is about REST API, webhooks, and MCP integrations for AI/automation, not about open mail protocol interoperability or data portability for switchers.

   ⚑ flag

   Fastmail✓fullcommunity8/10

   Fastmail documents JMAP (open standard) and IMAP/SMTP access via API tokens/app passwords, plus import/export tooling for migration, and community reports confirm SMTP/IMAP interoperability with other providers (e.g., fetching Gmail via IMAP, app passwords for SMTP). This directly supports open-protocol reachability and avoiding lock-in. Missing for 10: explicit documentation of full mail export/backup format standards (e.g., mbox/EML export) and independent verification of IMAP feature parity beyond anecdotal mentions.

   • [claimed-docs] “Fetch `/.well-known/jmap` for the session object - capabilities, accounts, and all API URLs.”
   • [claimed-docs] “JMAP is an open standard any organisation can implement, not more proprietary lock-in from big tech companies.”
   • [claimed-docs] “Open source and standards | Fastmail”
   • [claimed-docs] “API tokens”
   • [claimed-docs] “Import your mail”
   • [community] “As an alternative to forwarding, you can also configure Fastmail to fetch mail from (and send via) Gmail like a mail client.”
   • [community] “I just use SMTP for this (with FastMail). FastMail is not really intended for [transactional emails at scale] as the limits and the like don…”
   • [community] “Fastmail has an easy migration tool as well if you don't want to go the IMAP route. Now, migrating filters and rules over on the other hand.…”

   proof ↗⚑ flag

2. switcherSelf-host the email app and keep the mail pipeline under my own control

   weight 1 · round drawn
   Missive—none0/10

   Missive is a cloud-hosted SaaS collaboration/email platform with no documented self-hosting option; community evidence confirms mail data routes through Missive's own servers (missive-comm-1), and no docs mention on-premise or self-hosted deployment.

   • [community] “User asked if Gmail/Yahoo emails pass through Missive's servers. After being told TLS is used but data does route through Missive's servers,…”

   proof ↗⚑ flag

   Fastmail—none0/10

   The axis applies to this product kind (peer products hold positive or none verdicts on this story), so lack of evidence for an applicable capability is "none", never "na". (na/none harmonized at arena bring-up — see pipeline/scripts/na-harmonize.ts.)

   ⚑ flag

Agent access

1. ai-native userPoint an agent at llms.txt or agent-oriented docs

   weight 2 · round drawn
   Missive—none0/10

   Direct probes show no llms.txt, no docs.md, and no OpenAPI spec exposed at expected locations (all 404), and no evidence of agent-oriented documentation formats being offered elsewhere; while Missive has an MCP server (a different axis), there's no proof an agent can be pointed at llms.txt or similar agent-readable docs.

   • [probe] “PROBE llms.txt: HTTP 404 at https://missiveapp.com/llms.txt”
   • [probe] “PROBE docs-md: HTTP 404 at https://missiveapp.com/docs.md”
   • [probe] “PROBE openapi: all candidate paths 404 (https://missiveapp.com/openapi.json, https://missiveapp.com/swagger.json, https://missiveapp.com/api…”

   proof ↗⚑ flag

   Fastmail—none0/10

   A direct probe confirms no llms.txt exists (404) and no openapi/agent-oriented discovery docs were found either; while JMAP API docs exist, there is no evidence of an llms.txt or agent-oriented documentation entry point.

   • [probe] “PROBE llms.txt: HTTP 404 at https://www.fastmail.help/llms.txt”
   • [probe] “PROBE openapi: all candidate paths 404 (https://www.fastmail.help/openapi.json, https://www.fastmail.help/swagger.json, https://www.fastmail…”

   proof ↗⚑ flag

2. ai-native userRun the product headlessly / in CI for automation

   weight 2 · round to Fastmail
   Missive~partialprobed3/10

   Missive exposes a REST API, webhooks, and a documented MCP server that let external systems and AI agents trigger actions without using the UI, which could be scripted from CI/automation pipelines. However there is no evidence of an official CLI, headless mode, Docker/container deployment, or CI-specific documentation/examples for running Missive itself in automated pipelines. Missing for 10: dedicated CLI or headless execution mode, CI/CD integration guides, and independent confirmation of automation-in-CI use cases.

   • [claimed-docs] “Missive developer tools: REST API, UI integrations, webhooks, and custom channels for full customization.”
   • [claimed-docs] “Use the Rest API to enrich Missive conversations with content from anywhere: commits from GitHub, transactions from Stripe,”
   • [claimed-docs] “Automate your workflows”
   • [claimed-docs] “API & MCP access”
   • [probe] “official MCP server documented at https://missiveapp.com/docs/ai/mcp/server”

   proof ↗⚑ flag

   Fastmail~partialcommunity5/10

   Fastmail exposes a documented JMAP API and API tokens/OAuth for programmatic access (fastmail-docs-1,2,5,22,40), and community evidence confirms it can be driven via SMTP/app passwords for scripted/automated sending (fastmail-comm-11), which supports headless use in scripts or CI. However, there is no explicit CI/headless-mode documentation, no official CLI, and community feedback notes it isn't built for large-scale automated/transactional use. Missing for 10: dedicated CI/automation documentation or examples, an official CLI, and confirmation of headless reliability at scale.

   • [claimed-docs] “Fetch `/.well-known/jmap` for the session object - capabilities, accounts, and all API URLs.”
   • [claimed-docs] “Standard OAuth 2.0 or Bearer tokens. No custom auth protocol to implement. Works with what you already have.”
   • [claimed-docs] “API tokens”
   • [claimed-docs] “API Documentation”
   • [community] “I just use SMTP for this (with FastMail). FastMail is not really intended for [transactional emails at scale] as the limits and the like don…”

   proof ↗⚑ flag

3. ai-native userPlug MCP servers into this product so it can use their tools

   weight 3 · round to Missive
   Missive✓fullclaimed8/10

   Missive documents a clear custom-MCP flow: users add a 'Custom MCP' server with a URL and auth, and 'connect any MCP-compatible server to Missive's AI Copilot' to let the assistant use internal APIs, databases, or custom tooling, alongside pre-built MCP integrations (Notion, Linear, Attio, Lindy.ai). Missing for 10: independent/hands-on verification of the custom MCP connection flow beyond vendor docs, and more detail on tool invocation limits or reliability.

   • [claimed-docs] “Give your Missive AI Assistant access to internal APIs, databases, or custom tooling”
   • [claimed-docs] “Add "Custom MCP" and enter a name and your server URL. Choose an authentication method and click Add”
   • [claimed-docs] “Missive ships with ready-to-use MCP integrations for Notion, Linear, and Attio, plus AI automation platforms like Lindy.ai.”
   • [claimed-docs] “With custom MCP, you can connect any MCP-compatible server to Missive's AI Copilot and let AI interact with your internal systems, proprieta…”
   • [claimed-docs] “Connect any MCP-compatible server to Missive's AI Copilot and let AI interact with your internal systems, proprietary data, or homegrown too…”
   • [claimed-docs] “Extend capabilities beyond Missive's built-in MCP integrations”
   • [claimed-docs] “Missive ships with ready-to-use MCP integrations for Notion, Linear, and Attio, plus AI automation platforms like Lindy.ai. The assistant ru…”

   proof ↗⚑ flag

   Fastmail—none0/10

   The axis applies to this product kind (peer products hold positive or none verdicts on this story), so lack of evidence for an applicable capability is "none", never "na". (na/none harmonized at arena bring-up — see pipeline/scripts/na-harmonize.ts.)

   ⚑ flag

4. ai-native userConnect an agent via an official MCP server

   weight 3 · round to Missive
   Missive✓fullprobed9/10

   Missive explicitly documents an official MCP server that lets external AI apps (Claude, ChatGPT, Cursor) connect and act on conversations, contacts, calendar, and drafts with configurable permissions, and a dedicated docs page for the MCP server is confirmed to exist via probe. Missing for 10: independent/hands-on third-party confirmation that external agents successfully connect and operate via this server.

   • [claimed-docs] “External AI apps like Claude, ChatGPT, or Cursor can now connect to Missive through the Model Context Protocol and act on your conversations…”
   • [claimed-docs] “External AI apps like Claude, ChatGPT, or Cursor can now connect to Missive through the Model Context Protocol and act on your conversations…”
   • [probe] “official MCP server documented at https://missiveapp.com/docs/ai/mcp/server”
   • [claimed-docs] “API & MCP access”

   proof ↗⚑ flag

   Fastmail—none0/10

   Fastmail exposes JMAP and API tokens for developers, but there is no evidence of an official MCP server or endpoint that lets AI agents connect natively; probes for machine-readable spec files (llms.txt, openapi) both return 404.

   • [claimed-docs] “Fetch `/.well-known/jmap` for the session object - capabilities, accounts, and all API URLs.”
   • [claimed-docs] “API tokens”
   • [probe] “PROBE llms.txt: HTTP 404 at https://www.fastmail.help/llms.txt”
   • [probe] “PROBE openapi: all candidate paths 404 (https://www.fastmail.help/openapi.json, https://www.fastmail.help/swagger.json, https://www.fastmail…”

   proof ↗⚑ flag

5. ai-native userUse an official CLI

   weight 2 · round drawn
   Missive—none0/10

   Missive is an email/collaboration app offering REST API, webhooks, and MCP integrations, but no evidence anywhere in the pack mentions an official CLI tool for interacting with Missive. Probes for docs/openapi manifests return 404s, and no CLI-related changelog or docs entries exist.

   • [claimed-docs] “Missive developer tools: REST API, UI integrations, webhooks, and custom channels for full customization.”
   • [claimed-docs] “Missive developer tools: REST API, UI integrations, webh”
   • [probe] “PROBE llms.txt: HTTP 404 at https://missiveapp.com/llms.txt”
   • [probe] “PROBE docs-md: HTTP 404 at https://missiveapp.com/docs.md”
   • [probe] “PROBE openapi: all candidate paths 404 (https://missiveapp.com/openapi.json, https://missiveapp.com/swagger.json, https://missiveapp.com/api…”

   proof ↗⚑ flag

   Fastmail—none0/10

   Evidence shows JMAP API, tokens, and OAuth support, but there is no mention of an official CLI tool for Fastmail; probes for llms.txt/openapi also returned 404s, and no CLI is referenced anywhere in docs or community posts.

   ⚑ flag

6. ai-native userDrive the product through a documented public API

   weight 3 · round drawn
   Missive✓fullprobed8/10

   Missive documents a REST API, webhooks, UI integrations, and custom channels for developers (missive-docs-31/39/15), plus an official MCP server exposing conversations, contacts, calendar, and drafts to AI apps like Claude/ChatGPT/Cursor (missive-docs-1/20, missive-probe-4). This gives AI-native users a documented, programmatic way to drive the product beyond the UI. Missing for 10: a discoverable OpenAPI/swagger spec or llms.txt (all probed and 404'd) and independent third-party corroboration of API robustness.

   • [claimed-docs] “Missive developer tools: REST API, UI integrations, webhooks, and custom channels for full customization.”
   • [claimed-docs] “Missive developer tools: REST API, UI integrations, webh”
   • [claimed-docs] “Use the Rest API to enrich Missive conversations with content from anywhere: commits from GitHub, transactions from Stripe,”
   • [claimed-docs] “External AI apps like Claude, ChatGPT, or Cursor can now connect to Missive through the Model Context Protocol and act on your conversations…”
   • [claimed-docs] “External AI apps like Claude, ChatGPT, or Cursor can now connect to Missive through the Model Context Protocol and act on your conversations…”
   • [probe] “official MCP server documented at https://missiveapp.com/docs/ai/mcp/server”
   • [claimed-docs] “API & MCP access”

   proof ↗⚑ flag

   Fastmail✓fullclaimed8/10

   Fastmail publishes JMAP, an open, documented API protocol with a discoverable session endpoint, standard OAuth2/Bearer auth, API tokens, push via EventSource/WebPush, and a dedicated dev docs page (fastmail.com/dev), giving AI-native users a clear, standards-based way to programmatically drive the product. Missing for 10: no evidence of an OpenAPI/Swagger spec or llms.txt (probes returned 404s) and no independent third-party corroboration of API robustness beyond vendor docs.

   • [claimed-docs] “Fetch `/.well-known/jmap` for the session object - capabilities, accounts, and all API URLs.”
   • [claimed-docs] “Standard OAuth 2.0 or Bearer tokens. No custom auth protocol to implement. Works with what you already have.”
   • [claimed-docs] “Get instant push via EventSource — one connection, all mailboxes. Or use WebPush for mobile-compatible push, no permanent connection require…”
   • [claimed-docs] “Sync changes more easily, more efficiently, and much, much faster. A single HTTP roundtrip is often all that's required.”
   • [claimed-docs] “API tokens”
   • [claimed-docs] “POST a `methodCalls` array. Query, fetch, and send, all in one HTTP request.”
   • [claimed-docs] “API Documentation”
   • [claimed-docs] “Standard OAuth 2.0 or Bearer tokens. No custom auth protocol to implement.”

   proof ↗⚑ flag

7. ai-native userIssue scoped/least-privilege API credentials for an agent

   weight 2 · round to Fastmail
   Missive~partialclaimed5/10

   Missive's MCP integration explicitly notes external AI apps connect "with the permissions you choose" (missive-docs-20) and custom MCP setup lets you "choose an authentication method" (missive-docs-17), implying some scoped access control for agents. However, there's no documentation of granular API-key scopes, role-based permission tiers, or a dedicated credential-issuance UI for least-privilege agent access. Missing for 10: explicit scoped API key/token generation flow, documented permission levels/roles for agents, and independent confirmation that scoping is enforced in practice.

   • [claimed-docs] “External AI apps like Claude, ChatGPT, or Cursor can now connect to Missive through the Model Context Protocol and act on your conversations…”
   • [claimed-docs] “Add "Custom MCP" and enter a name and your server URL. Choose an authentication method and click Add”
   • [claimed-docs] “API & MCP access”
   • [claimed-docs] “Give your Missive AI Assistant access to internal APIs, databases, or custom tooling”

   proof ↗⚑ flag

   Fastmail~partialcommunity6/10

   Fastmail provides API tokens (fastmail-docs-5/22) and OAuth2/Bearer token support (fastmail-docs-2/41) for JMAP access, and community evidence confirms real-world scoped 'app passwords' limited to a single protocol like SMTP (fastmail-comm-11), showing least-privilege credential issuance works in practice. However, the docs are only titles with no detail on fine-grained scope configuration for agent-specific use cases, and there's no explicit agent/AI-oriented credential guidance. Missing for 10: detailed scope/permission granularity documentation, explicit agent-use-case guidance, and independent hands-on verification of scoping API tokens (not just app passwords) for AI agents.

   • [claimed-docs] “API tokens”
   • [claimed-docs] “API tokens – Fastmail”
   • [claimed-docs] “Standard OAuth 2.0 or Bearer tokens. No custom auth protocol to implement. Works with what you already have.”
   • [claimed-docs] “Standard OAuth 2.0 or Bearer tokens. No custom auth protocol to implement.”
   • [community] “I just use SMTP for this (with FastMail). FastMail is not really intended for [transactional emails at scale] as the limits and the like don…”

   proof ↗⚑ flag

8. ai-native userBuild against official SDKs

   weight 2 · round drawn
   Missive—none0/10

   Missive documents a REST API, webhooks, custom channels, and MCP integrations for developers, but no evidence anywhere mentions official client SDKs (e.g. language libraries) for building against Missive; probes even show 404s for OpenAPI/spec files that would typically back SDK generation.

   • [claimed-docs] “Missive developer tools: REST API, UI integrations, webhooks, and custom channels for full customization.”
   • [claimed-docs] “Missive developer tools: REST API, UI integrations, webh”
   • [probe] “PROBE openapi: all candidate paths 404 (https://missiveapp.com/openapi.json, https://missiveapp.com/swagger.json, https://missiveapp.com/api…”
   • [probe] “PROBE llms.txt: HTTP 404 at https://missiveapp.com/llms.txt”
   • [probe] “PROBE docs-md: HTTP 404 at https://missiveapp.com/docs.md”

   proof ↗⚑ flag

   Fastmail—none0/10

   Fastmail documents the JMAP protocol and a developer API page, but the evidence never mentions any official SDKs (client libraries) for languages/frameworks — only raw protocol specs, API tokens, and a dev docs page. Probes for machine-readable API discovery (llms.txt, openapi) also 404, reinforcing the absence of packaged SDK tooling.

   • [claimed-docs] “API Documentation”
   • [claimed-docs] “API tokens”
   • [probe] “PROBE llms.txt: HTTP 404 at https://www.fastmail.help/llms.txt”
   • [probe] “PROBE openapi: all candidate paths 404 (https://www.fastmail.help/openapi.json, https://www.fastmail.help/swagger.json, https://www.fastmail…”

   proof ↗⚑ flag

9. ai-native userSubscribe to events via webhooks

   weight 2 · round to Fastmail
   Missive~partialclaimed4/10

   Missive's developer tools page explicitly lists webhooks alongside REST API and custom channels, confirming the capability exists, but there is no detail on event types, subscription setup, payload format, or independent corroboration of webhook usage. Missing for 10: documented list of subscribable event types, webhook setup/config instructions, security/signing details, and third-party confirmation of reliability.

   • [claimed-docs] “Missive developer tools: REST API, UI integrations, webhooks, and custom channels for full customization.”
   • [claimed-docs] “Missive developer tools: REST API, UI integrations, webh”

   proof ↗⚑ flag

   Fastmail~partialclaimed5/10

   Fastmail's JMAP API supports push/event notification via EventSource (SSE) and WebPush, which lets clients subscribe to mailbox changes without polling — a webhook-adjacent mechanism (docs-3, docs-19). However, there's no explicit documentation of a classic webhook (HTTP callback URL registration) API, and no independent/hands-on confirmation of setting up such subscriptions. Missing for 10: explicit webhook callback-URL registration docs, third-party confirmation of push reliability, and any mention of 'webhook' terminology in official docs.

   • [claimed-docs] “Get instant push via EventSource — one connection, all mailboxes. Or use WebPush for mobile-compatible push, no permanent connection require…”
   • [claimed-docs] “Get instant push via EventSource — one connection, all mailboxes.”
   • [claimed-docs] “POST a `methodCalls` array. Query, fetch, and send, all in one HTTP request.”
   • [claimed-docs] “API Documentation”

   proof ↗⚑ flag

Agentic features

1. ai-native userGet AI-generated insights and suggestions from my data inside the product

   weight 2 · round to Missive
   Missive~partialclaimed5/10

   Missive's AI assistant can summarize inboxes, draft replies, and triage conversations against connected data (CRM, docs) via MCP, and can compose/reply/translate with AI, which counts as AI-generated insights/suggestions from data. However, evidence is mostly marketing copy without hands-on demonstration of proactive 'insights' (e.g., analytics-driven suggestions) and no independent corroboration of quality or accuracy. missing for 10: independent/hands-on verification of insight quality, concrete examples of proactive analytics-style insights beyond summarization/drafting, and detail on how suggestions are surfaced in UI.

   • [claimed-docs] “Ask Claude to summarize your inbox and draft replies without leaving the chat”
   • [claimed-docs] “Let an agent triage new conversations against your CRM before you look at them”
   • [claimed-docs] “Quickly compose, reply, and translate messages with AI directly in Missive.”
   • [claimed-docs] “Give your Missive AI Assistant access to internal APIs, databases, or custom tooling”
   • [claimed-docs] “With custom MCP, you can connect any MCP-compatible server to Missive's AI Copilot and let AI interact with your internal systems, proprieta…”

   proof ↗⚑ flag

   Fastmail—none0/10

   No evidence of any AI-generated insights, summaries, or suggestions within Fastmail's product; the evidence pack covers JMAP protocol, filters, search, aliases, masked email, and other traditional email features but nothing about AI-driven analysis of user data.

   ⚑ flag

2. ai-native userSet up automations that run autonomously in the background

   weight 2 · round to Missive
   Missive~partialclaimed7/10

   Missive documents rule-based workflow automation (up to 1000 rules) and long-running AI assistant sessions that operate in the background with a session tab showing progress ('no longer need babysitting'), plus agent-driven triage of conversations against a CRM before a human looks at them — evidence of autonomous background automation. However, there's no independent/hands-on confirmation of reliability or scope of autonomy, and details on triggers/scheduling for rules are thin. Missing for 10: independent corroboration of autonomous execution reliability, deeper documentation on rule triggers/scheduling and failure handling.

   • [claimed-docs] “Automate your workflows”
   • [claimed-docs] “Automate your workflows Up to 1000 rules”
   • [claimed-docs] “Up to 1000 rules”
   • [claimed-docs] “The session tab now shows what the assistant is up to, and a conversation links back to the sessions attached to it.”
   • [claimed-docs] “Long assistant sessions no longer need babysitting. The session tab now shows what the assistant is up to”
   • [claimed-docs] “Let an agent triage new conversations against your CRM before you look at them”
   • [claimed-docs] “External AI apps like Claude, ChatGPT, or Cursor can now connect to Missive through the Model Context Protocol and act on your conversations…”

   proof ↗⚑ flag

   Fastmail~partialclaimed5/10

   Fastmail's Filters & Rules feature provides server-side automation that runs autonomously in the background without user intervention, and JMAP API tokens plus EventSource/WebPush push notifications allow building custom automated workflows (e.g., an agent reacting to new mail events). However, there is no evidence of purpose-built AI-agent automation tooling, scheduled/triggered agent workflows, or third-party AI automation integrations. Missing for 10: dedicated AI/agent automation framework or examples, evidence of autonomous multi-step workflows beyond simple filters, independent confirmation of using JMAP for agentic background tasks.

   • [claimed-docs] “Filters & Rules”
   • [claimed-docs] “Filters & Rules – Fastmail”
   • [claimed-docs] “Get instant push via EventSource — one connection, all mailboxes. Or use WebPush for mobile-compatible push, no permanent connection require…”
   • [claimed-docs] “Get instant push via EventSource — one connection, all mailboxes.”
   • [claimed-docs] “API tokens”
   • [claimed-docs] “API tokens – Fastmail”
   • [claimed-docs] “POST a `methodCalls` array. Query, fetch, and send, all in one HTTP request.”

   proof ↗⚑ flag

3. ai-native userDelegate tasks to a built-in AI assistant inside the product

   weight 3 · round to Missive
   Missive✓fullclaimed7/10

   Missive documents a built-in AI Assistant/Copilot that can compose, reply, translate, triage conversations against CRM data, and run extended 'sessions' with a visible status tab, plus access internal tools via MCP — all delegatable from within the product (missive-docs-49, missive-docs-34, missive-docs-22, missive-docs-16, missive-docs-52). Missing for 10: independent/hands-on evidence of actual task delegation outcomes and more detail on assistant capabilities/limits beyond first-party changelog blurbs.

   • [claimed-docs] “Quickly compose, reply, and translate messages with AI directly in Missive.”
   • [claimed-docs] “Long assistant sessions no longer need babysitting. The session tab now shows what the assistant is up to”
   • [claimed-docs] “Let an agent triage new conversations against your CRM before you look at them”
   • [claimed-docs] “Give your Missive AI Assistant access to internal APIs, databases, or custom tooling”
   • [claimed-docs] “Give your AI assistant access to your own tools and internal systems, directly from Missive.”
   • [claimed-docs] “The session tab now shows what the assistant is up to, and a conversation links back to the sessions attached to it.”
   • [claimed-docs] “Ask Claude to summarize your inbox and draft replies without leaving the chat”

   proof ↗⚑ flag

   Fastmail—none0/10

   The axis applies to this product kind (peer products hold positive or none verdicts on this story), so lack of evidence for an applicable capability is "none", never "na". (na/none harmonized at arena bring-up — see pipeline/scripts/na-harmonize.ts.)

   ⚑ flag

4. ai-native userOperate the product with natural-language commands

   weight 2 · round to Missive
   Missive✓fullclaimed7/10

   Missive's AI Assistant/Copilot and MCP integration let users issue natural-language requests (e.g., 'Ask Claude to summarize your inbox and draft replies,' 'compose, reply, and translate messages with AI') and let external AI apps act on conversations, contacts, calendar, and drafts through natural language via Claude/ChatGPT/Cursor. The command bar also supports quick text-based commands for actions like snoozing. Missing for 10: independent/hands-on user validation of natural-language accuracy and no detailed listing of all supported natural-language actions beyond marketing copy.

   • [claimed-docs] “External AI apps like Claude, ChatGPT, or Cursor can now connect to Missive through the Model Context Protocol and act on your conversations…”
   • [claimed-docs] “External AI apps like Claude, ChatGPT, or Cursor can now connect to Missive through the Model Context Protocol and act on your conversations…”
   • [claimed-docs] “Ask Claude to summarize your inbox and draft replies without leaving the chat”
   • [claimed-docs] “Let an agent triage new conversations against your CRM before you look at them”
   • [claimed-docs] “Long assistant sessions no longer need babysitting. The session tab now shows what the assistant is up to”
   • [claimed-docs] “Quickly compose, reply, and translate messages with AI directly in Missive.”
   • [claimed-docs] “Ask how a feature works, how to set up a rule, or where a setting lives. The answer comes straight from the Missive documentation instead of…”
   • [claimed-docs] “Master the command bar: keyboard shortcuts and quick commands. You can use the following patterns to initiate a search: search searc sear se…”

   proof ↗⚑ flag

   Fastmail—none0/10

   No evidence of any natural-language command interface, chat assistant, or NL-to-action layer in Fastmail; the product exposes a structured JMAP API and traditional GUI/keyboard shortcuts, not NL commands. Probes for llms.txt and OpenAPI (which could hint at AI-native tooling) returned 404s, further indicating absence.

   • [probe] “PROBE llms.txt: HTTP 404 at https://www.fastmail.help/llms.txt”
   • [probe] “PROBE openapi: all candidate paths 404 (https://www.fastmail.help/openapi.json, https://www.fastmail.help/swagger.json, https://www.fastmail…”
   • [claimed-docs] “Keyboard shortcuts”

   proof ↗⚑ flag

Api quality

1. ai-native userExplore an interactive API reference with runnable examples

   weight 2 · round drawn
   Missive—none0/10

   Missive documents a REST API and developer tools, but there is no evidence of an interactive API reference or runnable examples; explicit probes for openapi/swagger specs all returned 404s, indicating no interactive API explorer exists.

   • [claimed-docs] “Use the Rest API to enrich Missive conversations with content from anywhere: commits from GitHub, transactions from Stripe,”
   • [claimed-docs] “Missive developer tools: REST API, UI integrations, webhooks, and custom channels for full customization.”
   • [probe] “PROBE openapi: all candidate paths 404 (https://missiveapp.com/openapi.json, https://missiveapp.com/swagger.json, https://missiveapp.com/api…”

   proof ↗⚑ flag

   Fastmail—none0/10

   Fastmail provides JMAP protocol documentation and a developer docs page (fastmail-docs-40), but there is no evidence of an interactive API reference with runnable/try-it-now examples; probes for OpenAPI/Swagger specs and llms.txt both returned 404s (fastmail-probe-1, fastmail-probe-2), indicating no such interactive tooling exists.

   • [claimed-docs] “API Documentation”
   • [probe] “PROBE llms.txt: HTTP 404 at https://www.fastmail.help/llms.txt”
   • [probe] “PROBE openapi: all candidate paths 404 (https://www.fastmail.help/openapi.json, https://www.fastmail.help/swagger.json, https://www.fastmail…”

   proof ↗⚑ flag

2. ai-native userDownload a machine-readable API spec (OpenAPI or equivalent)

   weight 2 · round to Fastmail
   Missive—none0/10

   Probes for OpenAPI/Swagger spec files at standard locations all returned 404, and no evidence pack item mentions a downloadable machine-readable API spec despite Missive having a REST API and developer docs.

   • [probe] “PROBE openapi: all candidate paths 404 (https://missiveapp.com/openapi.json, https://missiveapp.com/swagger.json, https://missiveapp.com/api…”
   • [claimed-docs] “Missive developer tools: REST API, UI integrations, webhooks, and custom channels for full customization.”
   • [claimed-docs] “Missive developer tools: REST API, UI integrations, webh”

   proof ↗⚑ flag

   Fastmail~partialprobed4/10

   Fastmail's JMAP protocol provides a machine-readable session/capabilities discovery endpoint (/.well-known/jmap) and points to formal JMAP specs, plus a general 'API Documentation' page, which partially satisfies the spirit of a machine-readable API description even though it isn't an OpenAPI document. However, direct probes for openapi.json/swagger.json/llms.txt all return 404, showing no actual downloadable OpenAPI-equivalent artifact is published. Missing for 10: an actual downloadable OpenAPI/Swagger/JSON-Schema file, confirmation that fastmail.com/dev/ hosts a structured machine-readable spec rather than prose docs, and independent verification of spec completeness.

   • [claimed-docs] “Fetch `/.well-known/jmap` for the session object - capabilities, accounts, and all API URLs.”
   • [claimed-docs] “API Documentation”
   • [probe] “PROBE llms.txt: HTTP 404 at https://www.fastmail.help/llms.txt”
   • [probe] “PROBE openapi: all candidate paths 404 (https://www.fastmail.help/openapi.json, https://www.fastmail.help/swagger.json, https://www.fastmail…”

   proof ↗⚑ flag

3. ai-native userTest against a sandbox environment without touching production data

   weight 1 · round drawn
   Missive—none0/10

   No evidence of any sandbox, staging, or test environment offered by Missive; all MCP/API access documented operates directly against live conversations, contacts, calendars, and drafts (missive-probe-rt-2), with no mention of a non-production mode for testing.

   ⚑ flag

   Fastmail—none0/10

   No evidence of a sandbox, staging, or test environment for developers to use with the JMAP API separate from production data; docs only describe production API access via OAuth/Bearer tokens.

   ⚑ flag

4. ai-native userRely on versioned APIs with a documented deprecation policy

   weight 2 · round drawn
   Missive—none0/10

   There is a REST API and MCP integrations documented, but no evidence of API versioning scheme or any documented deprecation policy; probes for openapi/spec files all 404. missing for 10: versioning scheme documentation, explicit deprecation/backward-compatibility policy, changelog of breaking API changes.

   • [claimed-docs] “Use the Rest API to enrich Missive conversations with content from anywhere: commits from GitHub, transactions from Stripe,”
   • [claimed-docs] “Missive developer tools: REST API, UI integrations, webhooks, and custom channels for full customization.”
   • [probe] “PROBE openapi: all candidate paths 404 (https://missiveapp.com/openapi.json, https://missiveapp.com/swagger.json, https://missiveapp.com/api…”

   proof ↗⚑ flag

   Fastmail—none0/10

   Evidence shows Fastmail's JMAP API and documentation (session discovery, OAuth, API tokens, dev docs) but no mention of API versioning scheme or a documented deprecation policy; probes for openapi/llms.txt also 404, suggesting no machine-readable spec exists either.

   • [claimed-docs] “Fetch `/.well-known/jmap` for the session object - capabilities, accounts, and all API URLs.”
   • [claimed-docs] “API Documentation”
   • [probe] “PROBE llms.txt: HTTP 404 at https://www.fastmail.help/llms.txt”
   • [probe] “PROBE openapi: all candidate paths 404 (https://www.fastmail.help/openapi.json, https://www.fastmail.help/swagger.json, https://www.fastmail…”

   proof ↗⚑ flag

Agent workflows

1. ai-native userAn external agent — Claude, ChatGPT, or my own — can read, triage, draft, and send my email end to end through a documented connection

   weight 2 · round to Missive
   Missive~partialprobed6/10

   Missive documents an official MCP server (missive-probe-4) that lets external AI apps like Claude, ChatGPT, or Cursor connect and act on conversations, contacts, calendar, and drafts with configurable permissions (missive-docs-1, missive-docs-20), including summarizing inboxes, drafting replies, and triaging conversations against a CRM (missive-docs-21, missive-docs-22). However, explicit end-to-end 'send' capability via the agent is not directly documented, and there is no independent/hands-on corroboration of the full read-triage-draft-send loop working in practice. Missing for 10: explicit documentation of agent-initiated sending (not just drafting), and third-party/hands-on verification of the full workflow.

   • [claimed-docs] “External AI apps like Claude, ChatGPT, or Cursor can now connect to Missive through the Model Context Protocol and act on your conversations…”
   • [claimed-docs] “External AI apps like Claude, ChatGPT, or Cursor can now connect to Missive through the Model Context Protocol and act on your conversations…”
   • [claimed-docs] “Ask Claude to summarize your inbox and draft replies without leaving the chat”
   • [claimed-docs] “Let an agent triage new conversations against your CRM before you look at them”
   • [claimed-docs] “With custom MCP, you can connect any MCP-compatible server to Missive's AI Copilot and let AI interact with your internal systems, proprieta…”
   • [claimed-docs] “Connect any MCP-compatible server to Missive's AI Copilot and let AI interact with your internal systems, proprietary data, or homegrown too…”
   • [probe] “official MCP server documented at https://missiveapp.com/docs/ai/mcp/server”

   proof ↗⚑ flag

   Fastmail~partialprobed5/10

   Fastmail exposes a fully documented JMAP API with OAuth2/Bearer token auth and API tokens (fastmail-docs-1,2,5,38,41) that could let a custom-built agent read, query, and send mail via standard HTTP, satisfying the 'my own agent' case. But there is no evidence of an official MCP server, ChatGPT/Claude connector, or any first-party documented integration enabling Claude or ChatGPT specifically to triage/draft/send end-to-end — probes for llms.txt and OpenAPI discovery both returned 404 (fastmail-probe-1, fastmail-probe-2). Missing for 10: official MCP server or Claude/ChatGPT plugin, documented end-to-end agent workflow (triage+draft+send), and independent evidence of an AI agent actually operating through this API.

   • [claimed-docs] “Fetch `/.well-known/jmap` for the session object - capabilities, accounts, and all API URLs.”
   • [claimed-docs] “Standard OAuth 2.0 or Bearer tokens. No custom auth protocol to implement. Works with what you already have.”
   • [claimed-docs] “API tokens”
   • [claimed-docs] “POST a `methodCalls` array. Query, fetch, and send, all in one HTTP request.”
   • [claimed-docs] “Standard OAuth 2.0 or Bearer tokens. No custom auth protocol to implement.”
   • [probe] “PROBE llms.txt: HTTP 404 at https://www.fastmail.help/llms.txt”
   • [probe] “PROBE openapi: all candidate paths 404 (https://www.fastmail.help/openapi.json, https://www.fastmail.help/swagger.json, https://www.fastmail…”

   proof ↗⚑ flag

Ai assistant

1. ai-native userAsk an assistant questions across my whole inbox and calendar — who said what, what's outstanding — and get grounded answers

   weight 2 · round to Missive
   Missive~partialclaimed6/10

   Missive's AI Assistant/MCP integration lets external AI apps (Claude, ChatGPT, Cursor) act on conversations, contacts, calendar, and drafts, and docs explicitly mention asking Claude to summarize the inbox and draft replies — directly supporting cross-inbox Q&A grounded in Missive data. However, evidence doesn't demonstrate calendar-specific querying depth or explicit 'what's outstanding' style aggregate reasoning across the whole inbox, and there's no independent/hands-on validation of answer groundedness or accuracy. Missing for 10: concrete examples of calendar-integrated Q&A, evidence of multi-conversation aggregate answers, and independent corroboration of answer quality/groundedness.

   • [claimed-docs] “External AI apps like Claude, ChatGPT, or Cursor can now connect to Missive through the Model Context Protocol and act on your conversations…”
   • [claimed-docs] “External AI apps like Claude, ChatGPT, or Cursor can now connect to Missive through the Model Context Protocol and act on your conversations…”
   • [claimed-docs] “Ask Claude to summarize your inbox and draft replies without leaving the chat”
   • [claimed-docs] “Give your Missive AI Assistant access to internal APIs, databases, or custom tooling”
   • [claimed-docs] “With custom MCP, you can connect any MCP-compatible server to Missive's AI Copilot and let AI interact with your internal systems, proprieta…”

   proof ↗⚑ flag

   Fastmail—none0/10

   There is no evidence of any Fastmail-native AI assistant, chat interface, or grounded Q&A feature over inbox/calendar content; evidence only covers JMAP API access, standard mail features, and general product satisfaction. A third party could build such an assistant using JMAP/API tokens, but no evidence shows Fastmail itself offers this capability.

   • [claimed-docs] “Fetch `/.well-known/jmap` for the session object - capabilities, accounts, and all API URLs.”
   • [claimed-docs] “API tokens”
   • [claimed-docs] “API Documentation”

   proof ↗⚑ flag

Ai drafting

1. ai-native userAI drafts replies in my own voice and tone — ready to review and send, not generic boilerplate

   weight 3 · round to Missive
   Missive~partialclaimed4/10

   Missive documents AI compose/reply features ("Quickly compose, reply, and translate messages with AI directly in Missive" and "Ask Claude to summarize your inbox and draft replies") confirming AI drafting exists, but there is no evidence describing tone/voice personalization or that drafts are tuned to the user's own writing style versus generic boilerplate. Missing for 10: evidence of voice/tone learning or personalization, hands-on examples showing draft quality matches user's style, independent corroboration of draft usefulness.

   • [claimed-docs] “Quickly compose, reply, and translate messages with AI directly in Missive.”
   • [claimed-docs] “Ask Claude to summarize your inbox and draft replies without leaving the chat”
   • [claimed-docs] “Give your Missive AI Assistant access to internal APIs, databases, or custom tooling”

   proof ↗⚑ flag

   Fastmail—none0/10

   No evidence anywhere in the pack of AI-drafted replies, tone/voice matching, or generative reply features; Fastmail's evidence covers JMAP API, templates, filters, and general email management, not AI drafting.

   ⚑ flag

Ai triage

1. ai-native userAI triages my inbox for me — auto-labeling, categorizing, and surfacing what needs attention — with behavior I can steer and audit

   weight 3 · round to Missive
   Missive~partialclaimed6/10

   Missive's AI Assistant/MCP integration explicitly supports agent-driven triage ('Let an agent triage new conversations against your CRM before you look at them'), inbox summarization, and rule-based automation (up to 1000 rules), and provides audit trails via action logs and a session tab showing assistant activity, plus permission-scoped access for steering behavior. However, there's no explicit mention of automatic labeling/categorization as a distinct AI feature (only manual rules), and no independent/hands-on evidence confirming triage quality works as advertised. Missing for 10: explicit auto-labeling/categorization feature description, hands-on validation of triage accuracy, and clearer UI for reviewing/adjusting AI triage decisions beyond session logs.

   • [claimed-docs] “Let an agent triage new conversations against your CRM before you look at them”
   • [claimed-docs] “Ask Claude to summarize your inbox and draft replies without leaving the chat”
   • [claimed-docs] “The session tab now shows what the assistant is up to, and a conversation links back to the sessions attached to it.”
   • [claimed-docs] “Long assistant sessions no longer need babysitting. The session tab now shows what the assistant is up to”
   • [claimed-docs] “Every action within Missive is logged, so you know who did what, and when.”
   • [claimed-docs] “External AI apps like Claude, ChatGPT, or Cursor can now connect to Missive through the Model Context Protocol and act on your conversations…”
   • [claimed-docs] “Automate your workflows”
   • [claimed-docs] “Up to 1000 rules”

   proof ↗⚑ flag

   Fastmail—none0/10

   Evidence covers Fastmail's rule-based Filters & Rules, search, and JMAP API access, but there is no mention of AI-driven triage, auto-labeling, categorization, or a steerable/auditable AI assistant surfacing important emails. Absence of evidence for this applicable capability means it does not deliver the story.

   • [claimed-docs] “Filters & Rules”
   • [claimed-docs] “Filters & Rules – Fastmail”
   • [claimed-docs] “Searching your mail”

   proof ↗⚑ flag

1. ai-native userPerform bulk operations across many items at once

   weight 2 · round to Fastmail
   Missive~partialclaimed3/10

   Missive documents rule-based automation ('Up to 1000 rules') and API/MCP access that could act across many items, plus a bulk auto-archive list feature, but there is no direct evidence of a bulk-select/bulk-action UI or bulk API endpoint for acting on many conversations/contacts at once. Missing for 10: explicit bulk-action UI documentation, bulk API/webhook examples, and independent confirmation of scale-limits for automation across many items.

   • [claimed-docs] “Automate your workflows Up to 1000 rules”
   • [claimed-docs] “Up to 1000 rules”
   • [claimed-docs] “Picking Everyone in a shared account's Auto-archive list covers anyone who joins your organization later, instead of adding each person by h…”
   • [claimed-docs] “Use the Rest API to enrich Missive conversations with content from anywhere: commits from GitHub, transactions from Stripe,”
   • [claimed-docs] “Give your Missive AI Assistant access to internal APIs, databases, or custom tooling”

   proof ↗⚑ flag

   Fastmail~partialclaimed5/10

   JMAP's design (single HTTP request with a `methodCalls` array for query/fetch/send, fastmail-docs-38) inherently supports batching many operations together, and filters/rules (fastmail-docs-6) allow rule-based bulk processing of mail. However, there's no explicit documentation of a bulk-update/bulk-delete API pattern, no example of bulk operations across large item sets, and no independent evidence of this being used for AI-native bulk workflows. Missing for 10: explicit bulk operation API examples (e.g., bulk delete/move across many message IDs), documented limits/performance for large batches, and independent confirmation of successful bulk automation use.

   • [claimed-docs] “POST a `methodCalls` array. Query, fetch, and send, all in one HTTP request.”
   • [claimed-docs] “Filters & Rules”
   • [claimed-docs] “Sync changes more easily, more efficiently, and much, much faster. A single HTTP roundtrip is often all that's required.”

   proof ↗⚑ flag

2. ai-native userDefine rules that trigger actions automatically on events

   weight 3 · round drawn
   Missive~partialclaimed5/10

   Missive confirms a native Rules feature ("Automate your workflows", "Up to 1000 rules", and documentation referencing 'how to set up a rule') that lets users define automation triggered by events, plus webhooks/API for event-driven actions. However, the evidence pack lacks concrete documentation of what trigger events or actions rules support, no hands-on examples of rule configuration, and no independent corroboration of automation depth or reliability. missing for 10: detailed rule trigger/action catalog, hands-on walkthrough of rule creation, independent user validation of automation reliability.

   • [claimed-docs] “Ask how a feature works, how to set up a rule, or where a setting lives. The answer comes straight from the Missive documentation instead of…”
   • [claimed-docs] “Automate your workflows”
   • [claimed-docs] “Automate your workflows Up to 1000 rules”
   • [claimed-docs] “Up to 1000 rules”
   • [claimed-docs] “Missive developer tools: REST API, UI integrations, webhooks, and custom channels for full customization.”

   proof ↗⚑ flag

   Fastmail~partialcommunity5/10

   Fastmail's Filters & Rules feature lets users define rule-based automations (e.g., move/tag/forward on incoming mail conditions), which satisfies a basic version of 'rules trigger actions on events.' However, this is a traditional email-filter system, not framed for AI-native/agentic use, and there's no evidence of programmatic rule creation via API/JMAP, webhook-triggered actions, or AI-specific automation hooks beyond generic push/EventSource notifications. Missing for 10: API-driven rule creation/management, AI-agent-specific triggers or actions, and richer automation beyond mail filtering.

   • [claimed-docs] “Filters & Rules”
   • [claimed-docs] “Filters & Rules – Fastmail”
   • [claimed-docs] “Get instant push via EventSource — one connection, all mailboxes. Or use WebPush for mobile-compatible push, no permanent connection require…”
   • [community] “Fastmail has an easy migration tool as well if you don't want to go the IMAP route. Now, migrating filters and rules over on the other hand.…”

   proof ↗⚑ flag

3. ai-native userSchedule recurring jobs or workflows

   weight 2 · round drawn
   Missive—none0/10

   Missive documents an AI Assistant, MCP integrations, and an event-triggered 'rules' automation engine (up to 1000 rules) for workflows, but nothing in the evidence describes scheduling recurring/cron-style jobs or timed recurring AI workflows — rules appear to be trigger-based, not time-scheduled. missing for 10: any mention of a scheduler, cron-like recurrence, or time-based recurring job configuration for AI/assistant workflows.

   • [claimed-docs] “Automate your workflows”
   • [claimed-docs] “Automate your workflows Up to 1000 rules”
   • [claimed-docs] “Up to 1000 rules”
   • [claimed-docs] “Give your Missive AI Assistant access to internal APIs, databases, or custom tooling”
   • [claimed-docs] “With custom MCP, you can connect any MCP-compatible server to Missive's AI Copilot and let AI interact with your internal systems, proprieta…”

   proof ↗⚑ flag

   Fastmail—none0/10

   No evidence of scheduling recurring jobs/workflows; only email-specific automation like Filters & Rules, Scheduled Send (one-time), and Snooze are documented, none of which support recurring automated workflows or job scheduling via API/JMAP. missing for 10: recurring job/workflow scheduler, cron-like automation, evidence of JMAP being used to trigger scheduled/recurring tasks.

   • [claimed-docs] “Filters & Rules”
   • [claimed-docs] “Scheduled Send”
   • [claimed-docs] “Snooze messages to just when you need them. Whether it’s tickets to that stadium gig in September, or a bill due next Thursday, sometimes yo…”

   proof ↗⚑ flag

4. ai-native userVersion, review, and roll back my automations

   weight 1 · round drawn
   Missive—none0/10

   Missive documents rules/automations, an activity log, and AI session tabs, but there is no evidence of any version history, review workflow, or rollback mechanism for automations/rules — no changelog history for rules, no diff/versioning UI, no undo/rollback feature mentioned anywhere.

   ⚑ flag

   Fastmail—none0/10

   No evidence of any versioning, review, or rollback mechanism for automations (e.g., Filters & Rules history, change logs, or undo for automation configs); Fastmail's docs cover creating filters but nothing about version control or reverting changes.

   • [claimed-docs] “Filters & Rules”
   • [claimed-docs] “Filters & Rules – Fastmail”

   proof ↗⚑ flag

Calendar

1. power-userSee my calendar, respond to invites, and create events without leaving the email client

   weight 2 · round to Fastmail
   Missive~partialclaimed2/10

   The only calendar-related evidence is indirect: MCP changelog entries note that external AI apps can 'act on your conversations, contacts, calendar, and drafts,' implying Missive holds calendar data, but there is no documentation of an in-app calendar view, RSVP/invite response flow, or event-creation UI comparable to inbox features. Missing for 10: dedicated calendar panel/view docs, invite accept/decline UI, and event creation flow evidence — only an AI-assistant-access mention exists.

   • [claimed-docs] “External AI apps like Claude, ChatGPT, or Cursor can now connect to Missive through the Model Context Protocol and act on your conversations…”
   • [claimed-docs] “External AI apps like Claude, ChatGPT, or Cursor can now connect to Missive through the Model Context Protocol and act on your conversations…”

   proof ↗⚑ flag

   Fastmail✓fullclaimed7/10

   Fastmail's docs confirm built-in Calendar with event and invitation handling directly in the mail/webmail client (fastmail-docs-14/34), and JMAP supports calendar via CalDAV replacement (fastmail-docs-42), consistent with an integrated calendar app alongside email. However, evidence lacks hands-on/community confirmation of the invite-response and event-creation UX specifically. Missing for 10: independent/community corroboration of calendar RSVP and event-creation workflow, and detail on UI integration depth.

   • [claimed-docs] “Calendar events and invitations”
   • [claimed-docs] “Calendar events and invitations – Fastmail”
   • [claimed-docs] “JMAP is the open protocol that replaces IMAP (and CardDAV and CalDAV). It's faster, simpler, more powerful, and built for how email works to…”

   proof ↗⚑ flag

2. power-userShare my availability or insert bookable meeting times directly into an email

   weight 1 · round drawn
   Missive—none0/10

   The evidence pack shows Missive's MCP integration can 'act on... calendar' generally, but there is no mention of any feature to share availability, generate scheduling links, or insert bookable meeting times into an email — a distinct capability from generic calendar access.

   ⚑ flag

   Fastmail—none0/10

   The evidence only shows generic 'Calendar events and invitations' documentation (RSVP/invite handling) with no mention of an availability-sharing or booking-link feature akin to scheduling assistants; no docs or community reports describe inserting bookable meeting slots into emails.

   • [claimed-docs] “Calendar events and invitations”
   • [claimed-docs] “Calendar events and invitations – Fastmail”

   proof ↗⚑ flag

Sending

1. power-userSee whether and when recipients opened my email

   weight 1 · round drawn
   Missive—none0/10

   No evidence in the pack mentions read receipts, email open tracking, or notifications about recipient opens/views; the pack covers collaboration, MCP/AI integrations, and admin features but nothing about tracking email opens.

   ⚑ flag

   Fastmail—none0/10

   No evidence in the pack mentions read receipts, delivery/open tracking, or any similar feature in Fastmail's composing/sending tools or documentation.

   ⚑ flag

2. power-userSchedule an email to send later and undo a send within a grace window

   weight 2 · round to Fastmail
   Missive—none0/10

   No evidence in the pack mentions scheduled sending or an undo-send grace window; the pack covers MCP integrations, collaboration features, snoozing, and canned responses but nothing about send scheduling or send-delay/undo functionality.

   ⚑ flag

   Fastmail✓fullclaimed8/10

   Fastmail has dedicated first-party docs for both 'Scheduled Send' and 'Undo send' features, directly matching the story's requirements. Missing for 10: independent/hands-on corroboration of the undo grace-window mechanics or scheduling UX details beyond doc titles.

   • [claimed-docs] “Scheduled Send”
   • [claimed-docs] “Undo send”
   • [claimed-docs] “Scheduled Send – Fastmail”
   • [claimed-docs] “Undo send – Fastmail”

   proof ↗⚑ flag

Templates

1. power-userInsert saved snippets or templates — with variables and attachments — instead of retyping the same reply

   weight 2 · round to Missive
   Missive✓fullclaimed8/10

   Missive's canned responses/templates feature explicitly supports saving reusable replies, inserting them via keystrokes/command bar, sharing across teams, and customizing with a variables templating engine (recipient name, etc.), directly matching the story; MCP/API docs also confirm drafts resolve template variables like {{ user.name }}. missing for 10: explicit first-party documentation confirming attachments can be bundled/saved within a canned response/template, and independent hands-on corroboration of the templating workflow.

   • [claimed-docs] “Canned responses (or templates) are pre-written replies to common questions. Instead of typing the same answer repeatedly, you write it once…”
   • [claimed-docs] “You can easily customize your responses or templates with dynamic content like your recipient's name by using our variables templating engin…”
   • [claimed-docs] “Drafts created outside the composer, by the assistant, by a rule, or through the API and MCP server, now resolve {{ user.name }} and {{ user…”
   • [claimed-docs] “Drafts created outside the composer, by the assistant, by a rule, or through the API and MCP server, now resolve {{ user.name }} and {{ user…”

   proof ↗⚑ flag

   Fastmail~partialclaimed4/10

   Fastmail documents a dedicated "Templates" feature for saved replies, supporting the core ask of inserting canned text instead of retyping, but the evidence pack gives only the article title with no detail on variable substitution or attachment inclusion. missing for 10: documentation confirming template variables (e.g. name/date placeholders), attachment support within templates, and any independent/hands-on confirmation of these specifics.

   • [claimed-docs] “Templates”
   • [claimed-docs] “Templates – Fastmail”

   proof ↗⚑ flag

Offline

1. power-userRead, search, and write email offline, with changes syncing when I reconnect

   weight 2 · round to Fastmail
   Missive—none0/10

   No evidence in the pack addresses offline mode, local caching of email data, offline search, or sync-on-reconnect behavior; all citations concern MCP/AI integrations, team collaboration, and pricing features unrelated to offline reliability.

   ⚑ flag

   Fastmail~partialclaimed6/10

   Fastmail has a dedicated 'Offline support' help article and a documented behavior detail (snoozed messages only reappear once back online, implying local caching + resync), which supports reading/writing offline with sync on reconnect. However, the evidence pack only gives titles/snippets, not confirmation that full-text search works offline or exactly how conflict resolution/sync works, and there's no independent hands-on test confirming offline compose/search reliability. Missing for 10: detailed doc content on offline search, independent verification of offline write/compose queuing and reconnection sync behavior, and confirmation across web/mobile clients.

   • [claimed-docs] “Offline support”
   • [claimed-docs] “Offline support – Fastmail”
   • [claimed-docs] “If you're offline when a snoozed message is scheduled to return to your Inbox, you will not see the snoozed message reappear until you're ba…”
   • [claimed-docs] “Sync changes more easily, more efficiently, and much, much faster. A single HTTP roundtrip is often all that's required.”

   proof ↗⚑ flag

1. ai-native userDo everything through the API that I can do in the UI

   weight 2 · round to Fastmail
   Missive~partialprobed4/10

   Missive documents a REST API, webhooks, and an MCP server that can act on conversations, contacts, calendar, and drafts (missive-docs-15, missive-docs-31, missive-docs-45, missive-probe-4), suggesting broad but not explicitly complete UI/API parity — there is no vendor claim of 1:1 feature parity, and the OpenAPI spec could not be located via standard probes (missive-probe-3), making it hard to verify full API surface coverage against UI capabilities like snoozing, canned responses, or command-bar search (missive-docs-supp-1/3/4) which are not mentioned as API-exposed. Missing for 10: an explicit vendor statement of full UI/API parity, a discoverable OpenAPI/schema reference, and evidence that UI-only features (snoozing, canned responses, command bar actions) are also API-accessible.

   • [claimed-docs] “Use the Rest API to enrich Missive conversations with content from anywhere: commits from GitHub, transactions from Stripe,”
   • [claimed-docs] “Missive developer tools: REST API, UI integrations, webhooks, and custom channels for full customization.”
   • [claimed-docs] “Drafts created outside the composer, by the assistant, by a rule, or through the API and MCP server, now resolve {{ user.name }} and {{ user…”
   • [probe] “PROBE openapi: all candidate paths 404 (https://missiveapp.com/openapi.json, https://missiveapp.com/swagger.json, https://missiveapp.com/api…”
   • [probe] “official MCP server documented at https://missiveapp.com/docs/ai/mcp/server”
   • [claimed-docs] “Snoozing temporarily hides a conversation until a specific time, then brings it back to your Inbox. Use it to defer emails you can't deal wi…”
   • [claimed-docs] “Canned responses (or templates) are pre-written replies to common questions. Instead of typing the same answer repeatedly, you write it once…”

   proof ↗⚑ flag

   Fastmail~partialclaimed5/10

   Fastmail's JMAP API is well-documented for core mail operations (session discovery, OAuth, push via EventSource, single-roundtrip method calls) and JMAP also natively covers contacts/calendar, giving broad coverage beyond typical webmail APIs. However, the evidence never confirms API parity for many UI-only features referenced in docs (masked email management, snooze, templates, filters/rules configuration, scheduled send) — these are documented as UI/help features without corresponding API examples. missing for 10: explicit API endpoints/examples for masked email, snooze, filters, templates, scheduled send parity; independent developer confirmation that all UI actions are API-reachable.

   • [claimed-docs] “Fetch `/.well-known/jmap` for the session object - capabilities, accounts, and all API URLs.”
   • [claimed-docs] “Sync changes more easily, more efficiently, and much, much faster. A single HTTP roundtrip is often all that's required.”
   • [claimed-docs] “POST a `methodCalls` array. Query, fetch, and send, all in one HTTP request.”
   • [claimed-docs] “API Documentation”
   • [claimed-docs] “Masked Email”
   • [claimed-docs] “Filters & Rules”
   • [claimed-docs] “Snooze messages to just when you need them. Whether it’s tickets to that stadium gig in September, or a bill due next Thursday, sometimes yo…”

   proof ↗⚑ flag

2. ai-native userExport all of my data in open formats and leave

   weight 3 · round to Fastmail
   Missive—none0/10

   The evidence pack shows a REST API, webhooks, and MCP integrations for connecting external tools, but nothing documents a bulk data-export feature or open-format (mbox/CSV/JSON) export enabling a user to fully extract their mail, contacts, and conversation history and leave the platform. Probes for docs/API artifacts (llms.txt, openapi) also 404, further indicating no dedicated export-and-leave capability is documented.

   • [claimed-docs] “Use the Rest API to enrich Missive conversations with content from anywhere: commits from GitHub, transactions from Stripe,”
   • [claimed-docs] “Missive developer tools: REST API, UI integrations, webhooks, and custom channels for full customization.”
   • [probe] “PROBE llms.txt: HTTP 404 at https://missiveapp.com/llms.txt”
   • [probe] “PROBE docs-md: HTTP 404 at https://missiveapp.com/docs.md”
   • [probe] “PROBE openapi: all candidate paths 404 (https://missiveapp.com/openapi.json, https://missiveapp.com/swagger.json, https://missiveapp.com/api…”

   proof ↗⚑ flag

   Fastmail~partialclaimed4/10

   Fastmail's evidence shows JMAP is an open, non-proprietary standard with full API access (session object, method calls, OAuth tokens) that could in principle be used to pull out all mail data, and there's a dedicated 'Open source and standards' page, but there is no explicit documentation of a one-click full data export/backup feature (mail+contacts+calendar) for leaving the service — only 'Import your mail' guidance is evidenced. missing for 10: documented full-account export/backup tool covering mail, contacts, and calendar; explicit data-portability/GDPR export docs; independent confirmation of successful full export.

   • [claimed-docs] “JMAP is an open standard any organisation can implement, not more proprietary lock-in from big tech companies.”
   • [claimed-docs] “Open source and standards | Fastmail”
   • [claimed-docs] “Fetch `/.well-known/jmap` for the session object - capabilities, accounts, and all API URLs.”
   • [claimed-docs] “API Documentation”
   • [claimed-docs] “Import your mail”

   proof ↗⚑ flag

3. ai-native userRead the product's source under an open license

   weight 2 · round drawn
   Missive—none0/10

   Missive is a closed-source commercial email/collaboration SaaS; no evidence anywhere in the pack of an open-source license or public source repository, and probes for typical openness indicators (llms.txt, docs.md, openapi) all 404. No indication source code is available under any license.

   • [probe] “PROBE llms.txt: HTTP 404 at https://missiveapp.com/llms.txt”
   • [probe] “PROBE docs-md: HTTP 404 at https://missiveapp.com/docs.md”
   • [probe] “PROBE openapi: all candidate paths 404 (https://missiveapp.com/openapi.json, https://missiveapp.com/swagger.json, https://missiveapp.com/api…”

   proof ↗⚑ flag

   Fastmail—none0/10

   Fastmail is a proprietary commercial email service; while it supports open standards like JMAP and has a page titled 'Open source and standards' (fastmail-docs-23), there is no evidence that Fastmail's own product source code is published under an open license for users/AI agents to read.

   • [claimed-docs] “Open source and standards | Fastmail”
   • [claimed-docs] “JMAP is an open standard any organisation can implement, not more proprietary lock-in from big tech companies.”

   proof ↗⚑ flag

4. ai-native userSelf-host the core product

   weight 3 · round drawn
   Missive—none0/10

   Missive is a cloud-hosted SaaS collaboration/email product; evidence shows data routes through Missive's own servers (missive-comm-1) and no docs mention any self-hosting/on-prem deployment option anywhere in the extensive feature/pricing/docs pack.

   • [community] “User asked if Gmail/Yahoo emails pass through Missive's servers. After being told TLS is used but data does route through Missive's servers,…”

   proof ↗⚑ flag

   Fastmail—none0/10

   The axis applies to this product kind (peer products hold positive or none verdicts on this story), so lack of evidence for an applicable capability is "none", never "na". (na/none harmonized at arena bring-up — see pipeline/scripts/na-harmonize.ts.)

   ⚑ flag

1. ai-native userChoose where my data is stored (region/residency)

   weight 2 · round drawn
   Missive—none0/10

   No evidence in the pack mentions data residency, region selection, or geographic storage location controls; features like IP restrictions and SSO relate to access control, not data storage location. Missing for 10: any mention of regional data hosting options, residency guarantees, or storage location configuration.

   ⚑ flag

   Fastmail—none0/10

   The evidence pack contains no mention of data residency, regional storage options, or where Fastmail's servers/data centers are located; nothing addresses letting users choose a storage region. missing for 10: any documentation of regional data residency options, data center locations, or user controls for choosing where data is stored.

   ⚑ flag

2. ai-native userPrevent my data from being used to train AI models

   weight 3 · round drawn
   Missive—none0/10

   No evidence in the pack addresses any AI-training opt-out, data-usage policy for AI model training, or privacy controls specific to preventing training on user data. The pack covers MCP integrations, AI assistant features, and collaboration tools, but nothing about training data exclusion or a documented privacy commitment on this axis.

   ⚑ flag

   Fastmail—none0/10

   No evidence in the pack addresses AI training data usage, opt-out controls, or any explicit privacy commitment regarding AI model training on user email data. missing for 10: any AI-training data policy, opt-out mechanism, or explicit statement that user data is not used to train AI models.

   ⚑ flag

3. ai-native userControl data retention and deletion

   weight 2 · round drawn
   Missive—none0/10

   No evidence describes any data retention or deletion controls (e.g., configurable retention periods, right-to-delete, data purge options) for Missive or its AI/MCP features; the only related community note concerns data routing through servers via TLS, not retention/deletion policy.

   • [community] “User asked if Gmail/Yahoo emails pass through Missive's servers. After being told TLS is used but data does route through Missive's servers,…”

   proof ↗⚑ flag

   Fastmail—none0/10

   No evidence pack items address data retention policies, account deletion, data export/erasure controls, or AI-specific data handling for training/processing. The pack covers JMAP API, features, and general reviews but nothing on retention/deletion controls.

   ⚑ flag

4. ai-native userOpt out of telemetry and usage tracking

   weight 2 · round drawn
   Missive—none0/10

   No evidence pack item addresses telemetry/usage-tracking opt-out settings, privacy controls, or data-collection disclosures for Missive; the closest related content (comm-1) merely notes emails route through Missive's servers, which is unrelated to telemetry opt-out. This is an applicable axis for a SaaS product but no supporting evidence exists.

   ⚑ flag

   Fastmail—none0/10

   No evidence pack item discusses telemetry, usage tracking, analytics opt-out, or any privacy settings specific to AI-native data collection controls; the docs focus on JMAP/API features and general email functionality.

   ⚑ flag

Protection

1. switcherUse aliases or masked addresses so sign-ups and strangers never learn my real address

   weight 1 · round to Fastmail
   Missive—none0/10

   No evidence anywhere in the pack of email aliasing, masked/burner address generation, or similar identity-protection features for switchers; Missive is an email client/collaboration tool, and evidence covers team inboxes, MCP/AI integrations, and SSO, none of which address address masking.

   ⚑ flag

   Fastmail✓fullcommunity8/10

   Fastmail's Masked Email feature (fastmail-docs-18/29) directly delivers per-signup masked addresses so real address stays hidden, plus separate alias setup docs (fastmail-docs-12/36), and community testimony confirms real-world use for throwaway/sketchy sites (fastmail-comm-1). missing for 10: independent hands-on verification of masked-email creation flow beyond docs and a single community mention, and no detail on limits/edge cases of masked addresses.

   • [claimed-docs] “Masked Email”
   • [claimed-docs] “Masked Email – Fastmail”
   • [claimed-docs] “How to set up aliases”
   • [claimed-docs] “How to set up aliases – Fastmail”
   • [community] “Fastmail is fantastic, I've been a very happy customer for at least a couple years now. Masked emails have been so nice for throwaway/sketch…”

   proof ↗⚑ flag

2. switcherThe client protects me from senders' tracking — blocking read pixels by default — and is transparent about what it does with my mail data

   weight 2 · round drawn
   Missive—none0/10

   No evidence pack item mentions tracking-pixel blocking, image-loading proxying, or a documented privacy policy explaining what Missive does with mail data. The only related community evidence shows a user learning mail routes through Missive's servers and declining ('Thanks, but I pass'), which does not demonstrate a pixel-blocking feature or proactive transparency documentation.

   • [community] “User asked if Gmail/Yahoo emails pass through Missive's servers. After being told TLS is used but data does route through Missive's servers,…”

   proof ↗⚑ flag

   Fastmail—none0/10

   No evidence in the pack mentions blocking tracking pixels/read receipts, image proxying, or any specific transparency documentation about mail data handling; general privacy sentiment from community comments (fastmail-comm-3) is too vague to establish this specific capability.

   ⚑ flag

Migration

1. switcherImport my complete mail history and contacts from my old provider or client

   weight 1 · round to Fastmail
   Missive—none0/10

   No evidence in the pack discusses importing mail history or contacts from another provider/client (e.g., Gmail/Outlook migration, IMAP sync, contact import tools). Evidence covers AI/MCP features, collaboration, search filters, and pricing but nothing about onboarding migration or historical data import.

   ⚑ flag

   Fastmail~partialcommunity6/10

   Fastmail has a documented 'Import your mail' tool plus IMAP fetch/forwarding options for migrating mail from other providers, and community reports confirm an easy migration tool and IMAP-based fetching from Gmail. However, evidence does not clearly cover contacts import, and community feedback flags that filters/rules migration is notably harder ('migrating filters and rules over on the other hand...'). Missing for 10: explicit contacts-import documentation, confirmation of complete mail history fidelity, and stronger independent verification of a smooth full-history+contacts migration.

   • [claimed-docs] “Import your mail”
   • [claimed-docs] “Import your mail – Fastmail”
   • [community] “As an alternative to forwarding, you can also configure Fastmail to fetch mail from (and send via) Gmail like a mail client.”
   • [community] “Fastmail has an easy migration tool as well if you don't want to go the IMAP route. Now, migrating filters and rules over on the other hand.…”
   • [claimed-docs] “Move from Gmail”

   proof ↗⚑ flag

Search

1. power-userSearch is fast and precise — operators, filters, and ranked results across my full mail history

   weight 2 · round drawn
   Missive~partialclaimed3/10

   Evidence confirms Missive has search filters (Type: Internal/External, Date range) and a command-bar search that can query across messages, contacts, or a specific label, but there is no documentation of search operators (from:, subject:, boolean, etc.), relevance ranking, or explicit assurance of full-history indexing/performance at scale. Missing for 10: documented search operator syntax, ranked-results behavior, evidence of speed/precision across large mail archives, and independent corroboration of search quality.

   • [claimed-docs] “The Type (Internal / External) and Date range filters in search no longer stay greyed out until you enter a search term.”
   • [claimed-docs] “The Type (Internal / External) and Date range filters in search no longer stay greyed out until you enter a search”
   • [claimed-docs] “Master the command bar: keyboard shortcuts and quick commands. You can use the following patterns to initiate a search: search searc sear se…”

   proof ↗⚑ flag

   Fastmail~partialclaimed3/10

   Fastmail has a dedicated 'Searching your mail' help article confirming search is a first-class feature, and JMAP's fast query/fetch model implies backend efficiency, but the evidence pack never details actual search operators, filter syntax, ranking behavior, or performance across full mail history. missing for 10: documented search operator syntax (from:, subject:, has:attachment etc.), evidence of ranked/relevance-based results, benchmarks or user reports on search speed across large mail archives, independent corroboration of search precision.

   • [claimed-docs] “Searching your mail”
   • [claimed-docs] “Searching your mail – Fastmail”
   • [claimed-docs] “Sync changes more easily, more efficiently, and much, much faster. A single HTTP roundtrip is often all that's required.”
   • [claimed-docs] “POST a `methodCalls` array. Query, fetch, and send, all in one HTTP request.”

   proof ↗⚑ flag

Shortcuts

1. power-userDo everything from the keyboard — comprehensive shortcuts and a command palette — in an interface fast enough to never make me wait

   weight 3 · round to Missive
   Missive~partialcommunity6/10

   Missive documents a command bar (⌘/Ctrl+K) supporting search, snooze, and other quick commands, plus configurable swipe/keyboard shortcuts, which is direct evidence of keyboard-driven command palette functionality. However, there's no comprehensive shortcut list, no dedicated performance benchmarks, and community comments call the UI 'unintuitive' with 'design flaws' though also 'snappy' — mixed signal on speed/polish. Missing for 10: a full documented shortcut reference covering all major actions, explicit performance/latency claims, and independent hands-on confirmation of speed and keyboard completeness.

   • [claimed-docs] “You can also snooze by swiping a conversation (configurable in Settings > Preferences > Swipes), or by opening the command bar with ⌘/Ctrl +…”
   • [claimed-docs] “Master the command bar: keyboard shortcuts and quick commands. You can use the following patterns to initiate a search: search searc sear se…”
   • [community] “"We choose Missive for now because Missive feels like a proper snappy desktop app and is vastly cheaper ($15 vs $50 per user). Front feels l…”
   • [community] “"I fear that we will eventually switch to Front because Missive is unintuitive or (please someone build that) Gmail with collaboration featu…”

   proof ↗⚑ flag

   Fastmail~partialcommunity5/10

   Fastmail documents a dedicated keyboard shortcuts feature and JMAP-based sync architecture emphasizing speed, and community feedback corroborates the interface being notably fast ('a ton faster' than alternatives). However, there is no evidence of a command palette or comprehensive shortcut coverage claims, and no hands-on confirmation of full keyboard-only operation. Missing for 10: explicit command-palette feature, evidence of exhaustive/comprehensive shortcut coverage beyond a single help article, independent benchmarking of UI responsiveness under load.

   • [claimed-docs] “Keyboard shortcuts”
   • [claimed-docs] “Keyboard shortcuts – Fastmail”
   • [claimed-docs] “Sync changes more easily, more efficiently, and much, much faster. A single HTTP roundtrip is often all that's required.”
   • [community] “I switched from protonmail to fastmail recently. Fastmail was a ton faster and didn't randomly forget my sessions. Night and day to use. It …”
   • [community] “I recently moved my email to FastMail and I really like it. I even prefer its web interface over Gmail's.”

   proof ↗⚑ flag

Channels

1. team-leadThe same inbox also handles adjacent customer channels — SMS, WhatsApp, social, or live chat — beside email

   weight 1 · round to Missive
   Missive~partialclaimed6/10

   Pricing docs explicitly list "Email, SMS, social accounts" as channels handled in the same inbox, and developer docs mention support for "custom channels" via API, confirming Missive unifies email with at least SMS and social channels. However, there is no explicit evidence of native WhatsApp or live-chat channel support, only generic 'custom channels' extensibility. Missing for 10: explicit WhatsApp integration, native live-chat channel, and independent confirmation of multi-channel unification in practice.

   • [claimed-docs] “Email, SMS, social accounts”
   • [claimed-docs] “Missive developer tools: REST API, UI integrations, webhooks, and custom channels for full customization.”
   • [claimed-docs] “Missive developer tools: REST API, UI integrations, webh”

   proof ↗⚑ flag

   Fastmail—none0/10

   The axis applies to this product kind (peer products hold positive or none verdicts on this story), so lack of evidence for an applicable capability is "none", never "na". (na/none harmonized at arena bring-up — see pipeline/scripts/na-harmonize.ts.)

   ⚑ flag

Routing

1. team-leadAssign conversations to teammates and route incoming mail with rules so ownership is explicit

   weight 2 · round to Missive
   Missive✓fullclaimed8/10

   Missive's docs explicitly describe assigning conversations to a team or specific person while maintaining visibility (missive-docs-6), shared inboxes/distribution lists (missive-docs-32, missive-docs-28), and automated routing via rules (up to 1000 rules per missive-docs-11/25/36), directly matching the story's ask for explicit ownership assignment and rule-based routing. Missing for 10: independent/hands-on corroboration of rule-based mail routing in practice, and more detail on how rule conditions/criteria are configured.

   • [claimed-docs] “Assign conversations to a team or specific person, while maintaining visibility. And jump in, if needed.”
   • [claimed-docs] “Automate your workflows”
   • [claimed-docs] “Automate your workflows Up to 1000 rules”
   • [claimed-docs] “Up to 1000 rules”
   • [claimed-docs] “From distribution lists to shared inboxes”
   • [claimed-docs] “Have multiple people work out of the same inbox, without stepping on each other’s toes.”

   proof ↗⚑ flag

   Fastmail~partialclaimed3/10

   Fastmail's docs confirm mail routing via Filters & Rules, which lets a team-lead direct incoming mail to specific folders/addresses, but there is no evidence of any conversation-assignment feature (assigning a thread to a specific teammate with ownership tracking) anywhere in the pack. Missing for 10: conversation/ticket assignment to teammates, ownership/status indicators, any shared-inbox collaboration UI beyond basic filters.

   • [claimed-docs] “Filters & Rules”
   • [claimed-docs] “Filters & Rules – Fastmail”

   proof ↗⚑ flag

Shared inbox

1. team-leadWe can discuss an email in an internal side-thread — comments and @mentions beside the message — instead of forwarding copies around

   weight 2 · round to Missive
   Missive~partialclaimed5/10

   Missive's docs point to team collaboration around conversations — 'collaborate behind the scenes without changing your workflow', 'chat with your team' in groups/spaces, and 'compose emails together, get reviewed in real time' — which align with discussing a message internally rather than forwarding it. However, none of the evidence explicitly names a side-thread comment feature or @mention tagging mechanic attached to a message. missing for 10: explicit documentation of inline comment threads on conversations, explicit @mention functionality, and independent/hands-on confirmation that this replaces forwarding workflows.

   • [claimed-docs] “See what’s going on, know who’s doing what, and collaborate behind the scenes — without changing your workflow.”
   • [claimed-docs] “collaborate behind the scenes — without changing your workflow.”
   • [claimed-docs] “Chat with your team. In groups, dedicated team spaces, or one-on-one.”
   • [claimed-docs] “Chat with your team. In groups, dedicated team sp”
   • [claimed-docs] “Compose emails together, get reviewed in real time, and share attachments.”
   • [claimed-docs] “Assign conversations to a team or specific person, while maintaining visibility. And jump in, if needed.”

   proof ↗⚑ flag

   Fastmail—none0/10

   No evidence of any internal comment/annotation or @mention feature attached to emails in Fastmail; evidence only covers standard email features (filters, search, aliases, JMAP protocol) and none mention side-thread discussion or team collaboration around a message.

   ⚑ flag

2. team-leadMy team works shared inboxes together — shared accounts or team channels where everyone sees the same conversation state

   weight 3 · round to Missive
   Missive✓fullcommunity9/10

   Missive's core product docs directly describe shared/team inboxes with multiple people working the same inbox without conflict, conversation assignment while maintaining visibility, distribution-list-to-shared-inbox mapping, per-action audit logging, and dedicated team spaces/channels — exactly the shared-conversation-state model the story describes (missive-docs-6, missive-docs-9, missive-docs-19, missive-docs-28, missive-docs-32, missive-docs-35, missive-docs-30/48). Independent community commentary corroborates it is used specifically for team email collaboration (missive-comm-3), and no evidence contradicts the shared-inbox mechanics themselves (complaints found are about general UX/bugs, not this capability). Missing for 10: a hands-on third-party account specifically confirming real-time shared conversation-state syncing across users (vs. general collaboration praise).

   • [claimed-docs] “Assign conversations to a team or specific person, while maintaining visibility. And jump in, if needed.”
   • [claimed-docs] “Every action within Missive is logged, so you know who did what, and when.”
   • [claimed-docs] “Give each team a tailored space so they can seamlessly focus on their work.”
   • [claimed-docs] “Have multiple people work out of the same inbox, without stepping on each other’s toes.”
   • [claimed-docs] “From distribution lists to shared inboxes”
   • [claimed-docs] “Have multiple people work out of the same inbox, without stepping on each other's toes.”
   • [claimed-docs] “See what’s going on, know who’s doing what, and collaborate behind the scenes — without changing your workflow.”
   • [community] “"I love Streak for singleplayer but prefer Missive or Front for collaboration."”

   proof ↗⚑ flag

   Fastmail—none0/10

   Evidence covers JMAP protocol, personal productivity features, and multi-account login, but there is no mention of shared inboxes, team channels, or shared conversation state features for teams. Fastmail's docs reference 'Logging in to multiple accounts' which is about one user accessing several separate accounts, not shared team visibility into the same inbox.

   • [claimed-docs] “Logging in to multiple accounts”
   • [claimed-docs] “Logging in to multiple accounts – Fastmail”

   proof ↗⚑ flag

Followups

1. power-userSnooze conversations and set follow-up reminders that resurface a thread if nobody replies

   weight 2 · round to Missive
   Missive~partialclaimed6/10

   Missive's docs clearly document snoozing a conversation until a specific time so it resurfaces in the Inbox, including quick access via swipe or command bar (missive-docs-supp-1, missive-docs-supp-2). However, there is no evidence of a distinct 'follow-up reminder' feature that resurfaces a thread specifically if nobody replies (as opposed to a fixed snooze time) — the story's reply-tracking trigger is unevidenced. Missing for 10: documentation of a no-reply-triggered follow-up reminder mechanism, and any independent/hands-on confirmation of snooze/reminder reliability.

   • [claimed-docs] “Snoozing temporarily hides a conversation until a specific time, then brings it back to your Inbox. Use it to defer emails you can't deal wi…”
   • [claimed-docs] “You can also snooze by swiping a conversation (configurable in Settings > Preferences > Swipes), or by opening the command bar with ⌘/Ctrl +…”

   proof ↗⚑ flag

   Fastmail~partialclaimed5/10

   Fastmail's docs confirm a snooze feature that resurfaces messages at a chosen time, including behavior when offline, which covers the 'snooze conversations' half of the story. However there is no evidence of a 'nudge'/follow-up reminder that resurfaces a thread specifically if nobody replies — snoozing is time-based, not reply-tracking. missing for 10: evidence of a no-reply-triggered follow-up reminder feature, independent confirmation of snooze behavior beyond the offline-support note.

   • [claimed-docs] “Snooze messages to just when you need them. Whether it’s tickets to that stadium gig in September, or a bill due next Thursday, sometimes yo…”
   • [claimed-docs] “If you're offline when a snoozed message is scheduled to return to your Inbox, you will not see the snoozed message reappear until you're ba…”

   proof ↗⚑ flag

Inbox structure

1. power-userSelect many conversations at once and archive, label, or mark them done in one stroke

   weight 1 · round to Fastmail
   Missive—none0/10

   The evidence pack covers command bar search, snoozing, canned responses, MCP/AI assistant integration, and team collaboration features, but nothing documents multi-select bulk actions (archive/label/mark done across many conversations at once). Missing for 10: any docs or changelog entry describing bulk selection UI, keyboard multi-select, or batch archive/label/mark-done operations.

   • [claimed-docs] “You can also snooze by swiping a conversation (configurable in Settings > Preferences > Swipes), or by opening the command bar with ⌘/Ctrl +…”
   • [claimed-docs] “Master the command bar: keyboard shortcuts and quick commands. You can use the following patterns to initiate a search: search searc sear se…”

   proof ↗⚑ flag

   Fastmail~partialclaimed3/10

   Fastmail's documented Keyboard Shortcuts and Filters & Rules pages imply an interface that supports quick, multi-message actions, but no citation explicitly describes selecting multiple conversations for bulk archive/label/mark-done in one action. missing for 10: explicit documentation or hands-on evidence of multi-select checkboxes, bulk archive/label/mark-done actions, and confirmation of conversation-view group actions.

   • [claimed-docs] “Keyboard shortcuts”
   • [claimed-docs] “Keyboard shortcuts – Fastmail”
   • [claimed-docs] “Filters & Rules”
   • [claimed-docs] “Filters & Rules – Fastmail”

   proof ↗⚑ flag

2. power-userSplit my inbox into focused streams — important, team, newsletters, calendar invites — so triage happens in priority order, not arrival order

   weight 3 · round to Fastmail
   Missive~partialclaimed4/10

   Missive's docs mention rule automation (up to 1000 rules), team spaces, and shared/team inboxes, which could be used to organize conversations by category, but there is no explicit documentation of a dedicated 'streams' or 'focused inbox' feature that lets a user split a single inbox into priority-ordered views (important, team, newsletters, calendar invites) as described in the story. missing for 10: explicit inbox-view/stream creation feature, priority-based triage ordering, and evidence of calendar-invite handling as a distinct stream.

   • [claimed-docs] “Automate your workflows”
   • [claimed-docs] “Automate your workflows Up to 1000 rules”
   • [claimed-docs] “Up to 1000 rules”
   • [claimed-docs] “Give each team a tailored space so they can seamlessly focus on their work.”
   • [claimed-docs] “From distribution lists to shared inboxes”
   • [claimed-docs] “Assign conversations to a team or specific person, while maintaining visibility. And jump in, if needed.”

   proof ↗⚑ flag

   Fastmail~partialclaimed5/10

   Fastmail's Filters & Rules can route mail (e.g. newsletters, calendar invites) into separate folders/labels, and saved searches let a power-user build custom views, giving a rough approximation of prioritized streams — but the evidence never shows a dedicated multi-pane/tabbed 'focused inbox' UI or explicit stream-based triage ordering like Gmail's Priority Inbox or Outlook's Focused Inbox. missing for 10: a documented feature for simultaneous multi-stream inbox views, automatic 'important' classification, and evidence of ordering triage by priority rather than by folder/search separately.

   • [claimed-docs] “Filters & Rules”
   • [claimed-docs] “Filters & Rules – Fastmail”
   • [claimed-docs] “Searching your mail”
   • [claimed-docs] “Searching your mail – Fastmail”
   • [claimed-docs] “Calendar events and invitations”
   • [claimed-docs] “Calendar events and invitations – Fastmail”

   proof ↗⚑ flag