#1
Haraka is a fast, event-driven SMTP server for receiving, filtering, and relaying email, featuring a modular plugin architecture for customization at scale.
5.6k stars712 forksMITlast commit Actively maintained
5 self-hosted Postfix alternatives
Postfix is an open-source Mail Transfer Agent (MTA) that routes and delivers email via SMTP. It provides queue management, routing policies, TLS and SASL support and is commonly deployed on Unix-like servers; there is no single official Postfix SaaS offering.
Alternatives to Postfix
A small, C-based Mail Transfer Agent for local submission and outbound relay with TLS/SMTP authentication, aimed at home and small office use.
263 stars59 forkslast commit Likely dormant
OpenSMTPD is an open-source, minimal SMTP daemon from the OpenBSD project providing an RFC-compliant MTA with privilege separation, table backends, filters and TLS support.
Activity unknown
Open Source Sendmail provides a subset of Proofpoint's Sendmail Sentrion MTA for large-scale mail deployments; current release is 8.16.1 with a PGP-signed tarball and OpenDKIM integration.
Activity unknown
#5
chasquid is a minimalist SMTP server (MTA) for individuals and small groups, focused on secure defaults, easy configuration, and straightforward operation.
Activity unknown
What replacing Postfix actually involves
Every option on this page is open source and free to run on your own hardware, so you own the data and there is no subscription to cancel. 1 of 5 shipped a commit in the last six months. Licences in this list: MIT. In exchange you take on hosting, backups and updates yourself.
Browse everything in Email Servers (SMTP/IMAP).
