Migrating mail servers from exim to OpenSMTPD (smtpd) is fun and useful

Contributed by Peter N. M. Hansteen on 2026-05-15 from the delivery upgrade accepted dept.

Like (we suspect) quite a few of our readers, undeadly.org co-editor Peter Hansteen runs a mail service and settled on exim as the reasonable alternative to the classic sendmail way back when.

However, that software has had its share of security issues over the years, and during the preparations for the OpenBSD 7.9 release, the ports maintainers decided that

"History of security issues + setuid root is a terrible combo."

and it was time to remove exim from the packages collection.

This meant that the mail service needed to migrate to something else, and Peter wrote up a short article about migrating a multi-domain, multi-site setup to smtpd: OpenSMTPD Is The Mail Server For The Future. The article has a working configuration and advice on how to proceed.

Latest Articles

Sat, May 16
- 06:46 Migrating mail servers from exim to OpenSMTPD (smtpd) is fun and useful (0)
Wed, May 13
- 06:49 Automatic expiry at timeout for pf(4) overload tables (0)
Tue, May 12
- 11:52 Let's find out how to get predictable IPv6 addresses assigned to OpenBSD VMs (0)
- 05:26 Game of Trees 0.125 released (0)
Mon, May 11
- 20:20 Recent downtime (2)
Mon, Apr 20
- 08:58 LibreSSL 4.3.1 released (0)
- 05:32 OpenBSD -current is now "7.9-current" (0)
Wed, Apr 15
- 11:56 rpki-client 9.8 released (0)
- 05:00 Selectively block cores from the scheduler with sysctl hw.blockcpu (1)

Credits

Copyright © 2004-2008 Daniel Hartmeier. All rights reserved. Articles and comments are copyright their respective authors, submission implies license to publish on this web site. Contents of the archive prior to April 2nd 2004 as well as images and HTML templates were copied from the fabulous original deadly.org with Jose's and Jim's kind permission. This journal runs as CGI with httpd(8) on OpenBSD, the source code is BSD licensed. undeadly \Un*dead"ly\, a. Not subject to death; immortal. [Obs.]