username@domain login name for email account with virtualmin and postfix

For IMAP and POP3 authentication, all you have to do is change the “Format for usernames that include domain” in:

Virtualmin > System Settings > Server Templates > Default Settings > Mail for Domain

to be “user@domain”.

However, Cyrus SASL, which is what handles the SMTP authentication, requires a special flag on it to handle user@domain usernames, a -r in the settings. The magical file you need to edit is /etc/sysconfig/saslauthd. At the bottom you will see the following:

Additional flags to pass to saslauthd on the command line.
See saslauthd(8) for the list of accepted flags. FLAGS=-r

Just make your FLAGS= like mine does. This will pass the -r to the sasl authentication daemon, and your user@domain authentication will work!

Let me know if you have any other questions.

Originally found at :