Hello,
Frank> Would it be possible to configure something that will map an Frank> email address to the UNIX account name and use the account name Frank> for authentication and obtaining the related information (uid, Frank> gid, home dir)?
https://dovecot.org/pipermail/dovecot/2018-September/113025.html should be what you are looking for. I used that to map legacy accounts to username@domain accounts in SQL, but it should also work the other way round.
Florian
