OpenSMTPD is an implementation of the server-side SMTP protocol as defined by RFC 5321, with some additional standard extensions. It allows ordinary machines to exchange e-mails with other systems speaking the SMTP protocol.
Unsupported upstream version, likely has security bugs. Not removed immediately because of backwards incompatible configuration changes with the newer version in the tree. # Removal in 14 days. Bug #710754.
Jason A. Donenfeld <firstname.lastname@example.org> (2020-02-24)