OpenSMTPD 7.3 released June 17, 2023
Latest minor release:
released September 20, 2023
OpenSMTPD is a FREE implementation of
the server-side SMTP protocol
as defined by RFC 5321, with some additional standard extensions.
It allows ordinary machines to exchange emails with other systems speaking
the SMTP protocol.
Started out of dissatisfaction with other implementations, OpenSMTPD
is a fairly complete SMTP implementation.
OpenSMTPD is primarily developed by Gilles Chehade and Eric Faurot,
with contributions from various OpenBSD hackers and members from other communities.
OpenSMTPD is part of the OpenBSD Project.
The software is freely usable and re-usable by everyone under an ISC license.