User authentication in Dovecot/Postfix with user@domain

Published on 2018-01-15 15:20:09

I was having a problem in which I wanted to have email addresses with the same name but different domains, such as and Unfortunately Dovecot was stripping off the domain before checking the passwd file, which was less than ideal. The solution was in /etc/dovecot/conf.d/auth-passwdfile.conf.ext in the args for the passdb config. Changing username_format=%n to username_format=%u had the effect of asking dovecot to look the entire supplied username up in the passwd file, rather than just the user part. Of course I then had to edit all of the passwd file entries from user:{scheme}hash to user@domain:{scheme}hash, and then it all worked.