# postalsys/emailengine

Headless email client

Repository: https://github.com/postalsys/emailengine
Canonical: https://ross.abutalabs.com/products/emailengine
Homepage: https://emailengine.app/
Language: JavaScript
License: NOASSERTION
License Family: other
Last push: 2026-08-26T18:20:01+00:00

## Health v2 (maintenance only)
Score: 95/100 (v2, computed 2026-09-03T02:39:23.370411+00:00)
- activity 99, release rhythm 87, longevity 100
- inputs: {"age_days": 2378, "days_push": 7, "days_rel": 7, "gap_med": 5.0, "n_releases_24m": 115}
- flags: no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 2217, forks 226 (observed 2026-08-28T04:06:27.233805+00:00)

## What it is
EmailEngine is a self-hosted, source-available (not open-source) headless email client that exposes IMAP, SMTP, Gmail API, and Microsoft Graph through a unified REST API with real-time webhooks. It handles account onboarding via hosted OAuth2 forms, queued sending with tracking and bounce handling, and includes an admin dashboard, requiring a paid subscription beyond a 14-day trial.

## Use cases
- sync users' emails with my app without IMAP/MIME code
- send emails on behalf of users via one REST API
- get webhooks when new mail arrives in a mailbox
- connect Gmail and Outlook accounts with OAuth2 without building the flows
- monitor where test emails land (inbox placement)
- build a lightweight webmail or mobile email client
- integrate a support email account into my service
- let legacy SMTP/IMAP clients reach OAuth2-only mailboxes

## When to choose
- you need a unified email API across IMAP, Gmail, and Microsoft 365 providers
- you want real-time push notifications instead of IMAP polling
- you must keep email data on your own infrastructure (self-hosted)
- you want hosted OAuth2 onboarding so users never hand you passwords
- you're willing to pay a subscription for a production-grade email gateway

## When to avoid
- you need truly open-source software with a free license for commercial use
- you only need to send transactional email from your own address (a plain SMTP library like Nodemailer suffices)
- you want a fully managed hosted email API service
- you cannot run Redis or self-manage a server instance

## Facets
- artifact type: service
- maturity: active
- function: email, api-framework, http-server, webhook, auth, search-engine
- domain: email, apis, self-hosted, backend
- platform: windows, self-hosted
- tags: email-api, imap, smtp, gmail-api, microsoft-graph, source-available, webhooks, oauth2, email-sync, nodemailer, automation, nodejs, docker, linux, macos, web-server

## Member repositories
- postalsys/emailengine (main) score 95

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:06:27.233805+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T02:45:55.891999+00:00, confidence not recorded.
  - readme: https://github.com/postalsys/emailengine (fetched 2026-08-28T04:06:27.233805+00:00, sha ace58dcd7b35)
  - homepage: https://emailengine.app/ (fetched 2026-08-29T10:26:22.846018+00:00, sha f198bcb5504e)
  - site_page: https://learn.emailengine.app/docs/api/emailengine-api (fetched 2026-08-29T10:26:22.851215+00:00, sha 999f090fa775)
  - site_page: https://learn.emailengine.app/docs/support (fetched 2026-08-29T10:26:22.852935+00:00, sha cd2745f117db)
  - site_page: https://learn.emailengine.app/docs/installation (fetched 2026-08-29T10:26:22.854459+00:00, sha fddeab512cb5)
  - site_page: https://learn.emailengine.app/docs/api/post-v-1-authentication-form (fetched 2026-08-29T10:26:22.856875+00:00, sha b56cb46e5b60)
  - site_page: https://learn.emailengine.app/docs/installation/docker (fetched 2026-08-29T10:26:22.858952+00:00, sha 9ba5e3beecac)
  - site_page: https://learn.emailengine.app/docs/accounts/hosted-authentication (fetched 2026-08-29T10:26:22.861782+00:00, sha 7000e1a75c9d)
  - site_page: https://learn.emailengine.app/docs/webhooks/overview (fetched 2026-08-29T10:26:22.864492+00:00, sha 536c65ed828c)
  - site_page: https://learn.emailengine.app/ (fetched 2026-08-29T10:26:22.849037+00:00, sha 9826420e6f28)
- Data as of 2026-08-30T08:39:29.467469+00:00.