Poste.io

Poste.io provides a self‑hosted mail server that includes SMTP, IMAP and POP3 services together with built‑in anti‑spam and antivirus functionality. It implements modern authentication standards such as SPF, DKIM, DMARC and SRS, and ships a webmail client based on Roundcube over HTTPS. Administration is performed through a web interface that supports role‑based access, quota management, email redirection, autoreply and Sieve‑based filtering.

The system separates user data from binaries, storing mail configuration in a SQLite file that can be placed on external storage, which simplifies migration, backups and updates. Security features include TLS for all network connections, salted SHA‑512 password hashing, and container isolation via Docker. An integrated antivirus engine (ClamAV) and spam filter (RSPAMD) scan incoming messages for malware and unwanted content.

Installation is designed to be rapid, with a three‑step process that configures the server with reasonable defaults, allowing a functional email system to be operational in minutes without deep knowledge of mail server internals. The package is offered under a proprietary license with a free tier and no subscription requirement.