EmailEngine vs Postmark
EmailEngine
emailengine.app
Postmark
postmarkapp.comSide by side
| Figure | EmailEngine | Postmark |
|---|---|---|
| Price from | $120.83/mo | $5/mo |
| Free plan | — | Yes |
| Free trial | Yes | Yes |
| Open source | — | — |
| Web | Yes | Yes |
| Windows | Yes | — |
| macOS | Yes | — |
| Linux | Yes | — |
| API | Yes | Yes |
| Self-hosted | Yes | — |
| Plans published | 2 | 8 |
| Spec score · Email APIs | 8.6 (#4) | 8.6 (#6) |
| Security | Stored mailbox credentials and OAuth2 tokens can be encrypted with AES-256-GCM when the deployment’s EENGINE_SECRET key is configured. | Postmark supports TLS and HTTPS, DKIM, SPF, DMARC, two-factor authentication, API permission controls, penetration testing, and DDoS protection. |
| Support | The maker says support goes directly to the developer who wrote the code, and its annual subscription includes developer support. | Postmark offers support by email, live chat, and one-on-one calls and reports a 95% customer happiness rating. |
Plans
EmailEngine
- Annual subscription$1,450 a year
- Enterprise perpetual licencePriced on request
Postmark
- FreeFree
- Basic$15 a month
- Pro$16.50 a month
- Platform$18 a month
- Custom activity retention$5 a month
- DMARC monitoring$14 a month
- Dedicated IP$50 a month
- High-volume plansPriced on request
In their own words
EmailEngine
EmailEngine is a self-hosted email API that connects Gmail, Microsoft 365, and IMAP mailboxes through a unified REST API. It sends webhooks when mailbox messages or state change, and can send mail through the connected account’s SMTP server or provider API. Native integrations use the Gmail API and Microsoft Graph; authentication options include managed OAuth2, service accounts for Google Workspace, Microsoft 365 app-only access, and shared or delegated mailboxes. An optional MCP server, currently in beta, lets connected AI clients search, read, file, draft, and send email with approved access. The admin interface shows sync status and queue details, with a Prometheus endpoint and Grafana dashboard for operations. EmailEngine runs on the customer’s infrastructure, uses Redis for sync metadata, and fetches message bodies on demand rather than storing them. A server and Redis using the noeviction policy are required. The annual subscription is $1,450 a year, excluding VAT where applicable, and includes developer support; each installation can start a full-functionality 14-day trial without signup or a credit card.
Postmark
Postmark delivers and tracks application email as an alternative to SMTP or Sendmail. It separates transactional and broadcast messages into different Message Streams and IP infrastructure. Developers can send through REST API, SMTP, or multi-region SMTP routing, with official libraries for Node.js, Python, Rails, Ruby, PHP, and.NET. Inbound messages can be converted to JSON and sent to a webhook URL. Tracking includes delivery, bounces, spam, opens, and links, with event webhooks. Editable responsive templates cover transactional messages such as password resets, receipts, and invitations. The free Developer plan costs nothing, provides 100 emails per month, permits no overages, and does not expire. Basic starts at $15 a month for 10,000 emails per month; extra emails cost $1.80 per 1,000 and are calculated at the end of the billing cycle. Unused emails do not roll over. Postmark lists API and web access. Its iOS app was sunset in June 2025 and is no longer supported.