qmail is a secure, reliable, efficient, simple message transfer agent. It is designed for typical Internet-connected UNIX hosts. It was developed by D. J. Bernstein.
More info at https://notes.sagredo.eu/qmail-notes-185/smtp-auth-qmail-tls-forcetls-patch-for-qmail-84.html
This qmail distribution puts together netqmail-1.06 with the following patches (more info in the README file):
- Erwin Hoffmann's qmail-authentication patch v. 0.8.3, which updates the patches provided by Krysztof Dabrowski and Bjoern Kalkbrenner. It provides cram-md5, login, plain authentication support for qmail-smtpd and qmail-remote. http://www.fehcom.de/qmail/smtpauth.html##PATCHES
- Frederik Vermeulen's qmail-tls patch v. 20200107 implements SSL or TLS encrypted and authenticated SMTP. The key is now 4096 bit long and the cert will be owned by vpopmail:vchkpw http://inoa.net/qmail-tls/ The file update_tmprsadh was modified to chown all .pem files to vpopmail.
- Marcel Telka's force-tls patch v. 2016.05.15 optionally gets qmail to require TLS before authentication to improve security. You have to declare FORCETLS=0 if you want to allow the auth without TLS https://notes.sagredo.eu/files/qmail/patches/roberto-netqmail-1.06_force-tls/force-tls_marcel.patch
make
make setup check
You have to export SMTPAUTH in your run file if you want to do the auth. For example:
export SMTPAUTH="!"
README.auth file for more info.
You can find more info and ask for support here https://notes.sagredo.eu/qmail-notes-185/smtp-auth-qmail-tls-forcetls-patch-for-qmail-84.html.