Postal vs Stalwart Mail Server
| Tagline | Self-hosted mail delivery platform, a SendGrid/Mailgun alternative | Modern all-in-one mail server with JMAP, IMAP4, and SMTP in a single Rust binary |
| Category | Email & Newsletters | Email & Newsletters |
| Replaces | SendGrid | Gmail / Google Workspace, SendGrid, Mailchimp |
| GitHub stars | 17k | 15k |
| Language | Ruby | Rust |
| License | MIT | AGPL-3.0 |
| Self-host difficulty | 4/5 Involved | 3/5 Moderate |
| Deploy options | Docker Docker Compose Manual | Docker Docker Compose Manual |
| Managed hosting | ||
| Last updated | 2 days ago | 2 days ago |
| View repo | View repo |
Where each falls short
The honest trade-offs — what you give up with each, versus the proprietary tools they replace.
Postal
- You are responsible for IP reputation, warmup, and deliverability
- Requires MariaDB, RabbitMQ, and DNS/DKIM configuration to run
- No marketing-campaign UI — it is a delivery engine, not a newsletter builder
- Less hand-holding than managed providers for spam/blocklist issues
Stalwart Mail Server
- No built-in newsletter/broadcast campaign tooling
- Web admin UI is functional but less refined than commercial email service dashboards
- Third-party anti-virus (ClamAV) integration requires additional setup
- Community support only on the free tier; paid support plans are limited
Bottom line
Choose Stalwart Mail Server if you want the lower-effort setup; choose Postal for the larger community and ecosystem. Open each guide below for deploy steps and the full feature gap.
Stalwart Mail Server
Modern all-in-one mail server with JMAP, IMAP4, and SMTP in a single Rust binary