Alternatives to Exim
An open-source mail transfer agent for Unix systems with flexible routing and mail checking. The listings below can replace it for an important use case. Each note says what changes if you switch.
The original
Exim
An open-source mail transfer agent for Unix systems with flexible routing and mail checking.
Replacements
Listings that take over the same core job as Exim.
Postfix
A widely used open-source mail transfer agent for routing and delivering email.
Postfix is a widely used open-source MTA with a security-focused design and extensive documentation, packaged by most operating systems.
OpenSMTPD
A free SMTP server from the OpenBSD project for sending and receiving email.
OpenSMTPD comes from the OpenBSD project with a simpler configuration and a permissive ISC license instead of the GPL.
Mox
An all-in-one open-source mail server for low-maintenance self-hosted email.
Mox replaces a standalone MTA with one program covering SMTP, IMAP and webmail plus built-in DKIM, SPF and DMARC, but is less proven.
Similar software
Related functionality, not a direct replacement.
Dovecot
An open-source IMAP and POP3 server that stores mailboxes and serves them to mail clients.
Cyrus IMAP
An open-source email, contacts and calendar server with IMAP, JMAP, CalDAV and CardDAV support.
docker-mailserver
A complete mail server with SMTP, IMAP, antispam and antivirus, packaged as a single container.
Mailu
A full-featured self-hosted mail server delivered as a set of Docker images.
Google Postmaster Tools
Google's web dashboard for checking a sending domain's reputation and mail deliverability to Gmail.
