Self-hosted Communication - Email - Mail Transfer Agents software

Mail Transfer Agents (MTAs) - SMTP servers.

9 apps, ranked by GitHub stars weighted by maintenance health.

Haraka

Fast, highly extensible, and event driven SMTP server.

Actively maintained ★ 5.6k MIT ~$5/mo

OpenSMTPD

Secure SMTP server implementation from the OpenBSD project.

Actively maintained ★ 586 ISC ~$3.5/mo

DragonFly

Small MTA for home and office use. Works on Linux and FreeBSD.

Actively maintained ★ 266 BSD-3-Clause ~$3.5/mo

chasquid

SMTP (email) server with a focus on simplicity, security, and ease of operation.

Health unknown Apache-2.0 ~$3.5/mo

Courier MTA

Fast, scalable, enterprise mail/groupware server providing ESMTP, IMAP, POP3, webmail, mailing list, basic web-based calendaring and scheduling services.

Health unknown GPL-3.0 ~$3.5/mo

EmailRelay

Small and easy to configure SMTP and POP3 server for Windows and Linux.

Health unknown GPL-3.0 ~$3.5/mo

Exim

Message transfer agent (MTA) developed at the University of Cambridge.

Health unknown GPL-3.0 ~$3.5/mo

Postfix

Fast, easy to administer, and secure Sendmail replacement.

Health unknown IPL-1.0 ~$3.5/mo

Sendmail

Message transfer agent (MTA).

Health unknown Sendmail ~$3.5/mo