Email and newsletters decision
HEY
A technically capable developer can build a narrow, useful self-hosted replacement covering core workflows (screening, Imbox, Paper Trail, Feed, basic calendar), but replicating HEY’s full polish, deliverability, native apps, and brand-backed trust is substantial and operationally costly, so many users will prefer to keep paying.
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.
What a replacement has to do
- Receive email for a domain, screen first-time senders, surface important mail in an 'Imbox', store transactional mail in a 'Paper Trail', present newsletters as a Feed, and provide a simple calendar.
What it still won’t have
- Polished native apps and cross-platform clients
- HEY-branded @hey.com addresses
- HEY’s production-grade spam filtering and deliverability reputation
- Integrated paid support and account management
- Polish and UX refinements (Workflows, Collections, Cover Art, Speakeasy) out of the box
What remains hard
- Brand trust
is designed, built, and backed by 37signals ™ , the people behind Basecamp ™ and Fizzy ™
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 HEY-like email+calendar web service using Postfix (inbound), Dovecot (IMAP/POP optional), or a hosted inbound relay; PostgreSQL for metadata and full-text search (or Elasticsearch); object storage (S3) for attachments; a Next.js/React frontend; and a CalDAV-compatible calendar backend. Implement: (1) MX-based inbound delivery into user mailboxes, (2) Screener flow holding first-time senders with Accept/Reject actions, (3) message classification into Imbox / Paper Trail / Feed, (4) a scrollable multi-message reader UI, (5) outgoing SMTP via authenticated relay with attachment upload and download links, and (6) a simple calendar view integrated into the same UI. Out of scope: native mobile apps, providing @hey.com addresses, advanced machine-learning spam models, and production-grade deliverability reputation management. Include error handling, input validation, authentication, and automated tests (unit + integration) for all core flows.
How we checked
How the score was reached
- Partly verdict base52
- An open-source build was found+5
- 5 cited sources+3
- Price verified on pricing page+3
- Evidence score63
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 · 5
Every page the run actually retrieved.
- official productHEY — official product page
- official pricingHEY — Pricing
- official docsHEY — Features
- open sourcemailpile/Mailpile
- open sourceBillionmail/BillionMail
Integrity checks
What held up, and what did not.
