chasquid is an SMTP (email) server, written in #golang

chasquid is an SMTP (email) server.

It aims to be easy to configure and maintain for a small mail server, at the expense of flexibility and functionality.

It’s written in Go.


  • Easy to configure, hard to mis-configure in ways that are harmful or insecure (e.g. no open relay, clear-text authentication, etc.).
  • Tracking of per-domain TLS support, prevents connection downgrading.
  • SMTP UTF8 (international usernames).
  • IDNA (international domain names).
  • Hooks for easy integration with greylisting, anti-virus and anti-spam.
  • Multiple domains, with per-domain user database and aliases.
  • Multiple TLS certificates.
  • Suffix dropping (user+something@domain -> user@domain).
  • Easy integration with letsencrypt.
  • SPF checking.
  • Monitoring HTTP server, with exported variables and tracing to help debugging.