Email and newsletters decision
Missive
Building a narrow shared-inbox + comments + basic automations is realistic for a small team, but reproducing Missive’s full product (SOC2, polished integrations, native apps, scale, and support) is expensive and time-consuming.
Visit website↗Open-source builds that already do this
Every project below is open source and already does this job today. Fork one, self-host it, or take the parts you need - the build prompt further down assumes an empty file, and this is the shortcut past that. Licences differ; check the one on each card before you ship. All Missive alternatives, with the arithmetic →
What a replacement has to do
- Provide a shared/team inbox where messages from multiple accounts appear in a unified view, allow internal threaded comments and assignment, and let users send/reply from connected accounts.
What it still won’t have
- SOC 2 compliance and audited security posture
- Production-grade scalability and multi-device native apps
- Built-in SSO/SAML and IP restrictions out of the box
- Polished integrations catalogue and sandboxed MCP connectors
- Vendor support, onboarding sessions, and migration assistance
What remains hard
- Product polish and ongoing maintenance
First-year cost
Keep paying
Paying is—cheaper in year one.
On cash alone, building overtakes the subscription at 5 seats.
Money you would actually spend
Time you would spend
—
What you would spend
What we assumed
The verdict above measures whether you could build it. This one is only about money.
Runnable build prompt
Build a minimal self-hosted team inbox web app using: PostgreSQL, Node.js (Express), a React frontend, and Sidekiq-like background workers (BullMQ). Core features in scope: 1) Connect Gmail via OAuth and generic IMAP/SMTP for inbox sync (incremental sync + send); 2) Unified inbox UI showing conversations and messages; 3) Internal threaded comments and collaborative drafting on a conversation; 4) Conversation assignment and simple task metadata (assignee, due date, status); 5) Basic automations: rule engine that can tag or assign based on sender/subject; 6) Webhook endpoint for inbound messages and admin UI for users and seats. Out of scope: mobile/desktop native apps, SOC 2 certification, enterprise SAML integrations, multi-provider AI assistant. Include robust error handling for email delivery/sync failures, retries for background jobs, and tests for mailbox syncing, assignment, comment creation, and automations. Provide Docker Compose for local dev and deployment instructions to a single managed VM (e.g., DigitalOcean) with TLS.
How we checked
How the score was reached
- Partly verdict base52
- An open-source build was found+5
- 4 cited sources+3
- Price verified on pricing page+3
- 3/3 assessment runs agreed+4
- Evidence score67
The base comes from the verdict. Everything under it is a check that either happened or did not, and each one is a fact frozen in this record rather than a judgement made at render time - so the same evidence always produces the same number.
How scoring works →Cited sources · 4
Every page the run actually retrieved.
- official productMissive — product home
- official pricingMissive pricing
- official docsMissive features
- open sourceun/inbox
Integrity checks
What held up, and what did not.
