Playing with qmail-spp
qmail-spp provides plug-in support for qmail-smtpd. It allows you to write external programs and use them to check SMTP command argument validity. The plug-in can trigger several actions, like denying a command with an error message, logging data, adding a header...
Greylisting for qmail
Greylisting is a method of defending e-mail users against spam. A mail transfer agent (MTA) using greylisting will "temporarily reject" any email from a sender it does not recognize. If the mail is legitimate, the originating server will try again after...
Denying bad DNS HELO/EHLOs
[If you followed the 'quick configuration' based on the config-all script, this feature was already configured for you at that time with the default settings.] Changelog Feb 9, 2025- clang compat- dropped I and V options Aug 17, 2023- C++ version Aug 13, 2023- v....