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EmailEngine

EmailEngine is a headless, source-available email API that exposes IMAP, SMTP, Gmail, and Microsoft Graph mailboxes through a unified REST interface, so you…

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EmailEngine is a headless, source-available email API that exposes IMAP, SMTP, Gmail, and Microsoft Graph mailboxes through a unified REST interface, so you can sync, monitor, and send email on behalf of your users or a dedicated account. It suits developers wiring their own services to real email; a free 14-day trial is included, after which a paid subscription is required.

Platform availability

Available on 2 of 9 platforms

  • Unraid
  • TrueNAS (not listed)
  • Umbrel (not listed)
  • ZimaOS (not listed)
  • Proxmox (not listed)
  • Helm (not listed)
  • Mac
  • Windows (not listed)
  • Linux (not listed)

Health score?A 0-100 score computed nightly from four factors: maintained (40%: recent commits and steady activity), popular (25%: GitHub stars, log scale), easy to install (20%: platforms, install notes, setup guides, Docker image) and light to run (15%: minimum RAM, ARM support). When the source code has been checked, a fifth factor, security check (20%: automated scan for committed secrets, unsafe desktop-app settings, known-vulnerable dependencies and project hygiene; any serious finding caps it at 20), is added. Factors without data are left out and the rest are rescaled.

75/100 Good

Maintained
100last commit 8 days ago
Popular
672,237 GitHub stars
Easy to install
452 install platforms, install notes, Docker image
Light to run
602 GB minimum RAM, runs on ARM

Availability: platform listings confirmed today, links checked 12 days ago

GitHub stars
2,237
Open issues
1
Last commit
2026-10-07
Latest release
v2.82.2
Activity
declining

Checked 8 days ago - source: GitHub (postalsys/emailengine)

Resources & Compatibility

Minimum requirements: 2 GB RAM, 1 CPU core(s), 10 GB disk. ARM (e.g. Raspberry Pi) is supported.

Checked 17 days ago - source: Docker Hub image tags and published docs

First-install notes

  • Install and start Redis before launching Install and start Redis (a fast in-memory database) before launching EmailEngine, then run the ping test that should return PONG; EmailEngine requires Redis to keep track of its data, so skipping this makes the app fail or behave unpredictably. source
  • Set Redis address and admin password hash In EmailEngine's settings file, set EENGINE_REDIS to the Redis address and put a generated hash (a scrambled password value) in EENGINE_PREPARED_PASSWORD, not your plain password; wrong values can break the app or prevent password login because EmailEngine uses these settings to find Redis and verify the password. source
  • If using Docker, map port 3000 If you run EmailEngine in Docker (a virtual container that runs the app separately), map port 3000 and set EENGINE_REDIS to redis://host.docker.internal:6379/8; without the mapping you cannot open the web interface, and without the host address the container cannot find Redis on your host. source
  • Licensing Each instance ships with a free 14-day trial; a paid subscription is required to keep running beyond the trial. source

Fetched today - each note links to its source

Alternatives (4)

  • Mailgun - Mailgun is email automation for developers.
  • Postmark - Postmark is a fast and reliable transactional email service.
  • Resend.com - Build, test, and send transactional emails at scale.
  • Sendgrid - Scalable email delivery for transactional email SendGrid transparently handles DKIM, SPF, ISP rate limits, content inspection, bounces, and…

Checked 14 days ago - source: AlternativeTo

Common questions

Do I need Redis before starting EmailEngine?

Yes. Install and start Redis before launching, and the Redis ping test should return PONG. EmailEngine uses Redis to track data, so skipping it can make the app fail or behave unpredictably.

How should I configure the EmailEngine admin password?

Set EENGINE_REDIS to your Redis address and put a generated hash in EENGINE_PREPARED_PASSWORD, not the plain password. Wrong values can break the app or prevent password login.

Which port should I expose for the EmailEngine web interface in Docker?

Map port 3000. Without the mapping, you cannot open the web interface.

How can my application learn about new incoming mail?

Use EmailEngine webhooks for real-time notifications.

Answers sourced from learn.emailengine.app, learn.emailengine.app, learn.emailengine.app, learn.emailengine.app

Community

Collected 16 days ago - public community threads