Everything a mail server needs, in one image.
The components below are the ones the internet has been running for years. poste.io versions them together, tests them together and ships them as one container.
- SMTP
- 25 · 587 · 465
- IMAP
- 143 · 993
- POP3
- 110 · 995
- Webmail & admin
- HTTPS
- Deployment
- 1 container
How it is built
-
01
Fast deployment
Run a complete mail server without assembling and maintaining a dozen unrelated services yourself. Reasonable defaults, a setup wizard, and no decisions that quietly break email six months later. docker run → working mail server
-
02
Your data stays yours
Mail and configuration live on a volume you own, strictly separated from the binaries. The user database is a single SQLite file. Backups, migration and updates are file operations, on your infrastructure. /data on your disk
-
03
Sensible security defaults
TLS everywhere, so no credentials or mail cross the internet in the clear. Passwords stored as salted SHA512. Old insecure authentication methods were traded away deliberately. SPF · DKIM · DMARC · SRS
What is inside the container
| Component | Purpose |
|---|---|
| Haraka | SMTP server |
| Dovecot | IMAP and POP3 server |
| Rspamd | Spam detection |
| ClamAV | Antivirus engine |
| Roundcube | Webmail client |
| NGiNX | Web server for administration and webmail |
| SQLite | User database in a single file, no running daemon |
| Z-Push | Open implementation of ActiveSync |
In the box
- SMTP — 25, 465, 587
- IMAP — 143, 993
- POP3 — 110, 995
- Webmail on HTTPS
- Redirects and aliases
- Vacation and autoreply
- Sieve filtering
- Autodiscovery
Security
- SPF, DKIM, DMARC
- SRS forwarding
- Spam filtering
- Antivirus
- TLS on every protocol
- Salted SHA512 passwords
- Outbound spam block PRO
Administration
- Web administration
- REST API
- Mailbox quotas
- Per-mailbox settings
- Domain administrators PRO
Domains & DNS
- Unlimited domains
- Unlimited mailboxes
- DKIM key management
- DNS domain diagnostics PRO
- Mail server diagnostics PRO
- DNSBL checker PRO
Operations
- One container to upgrade
- Data on its own volume
- Delivery queue
- Delivery log viewer PRO
- User log viewer PRO
- DMARC report viewer PRO
- Remote monitoring
Support
- Documentation
- Email support PRO
- Account transfer PRO+
- Managed installation PRO+
Items tagged PRO or PRO+ belong to the paid editions. See the full comparison.
01 Domain with DKIM
02 DNS diagnostics
03 Delivery log