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 | 13k |
| 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 | 9 days ago | today |
| 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. Stalwart Mail Server has seen more recent development. 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