I configured in the archive dovecot.conf the parameter auth_username_format = "%Ld_%Ln" because the users of my server have access yours e-mail accounts based in /etc/passswd where they are registered in format domain.com_user. This configuration work without problems via pop3 and imap (squirrelmail). My server is CentOS 5.0 and dovecot is 1.0.rc15.
The problem that occurs currently is: when the users go to have access the interface of change preferences (ISPCONFIG) where the supplied data of authentication are not the data of the email account (eg. user@domain.com) and yes of /etc/passwd the dovecot inserts underscore before the domain (eg. _domain.com_user) when it would have to make this only between the domain and the user.
Exists a way to solve this problem?
Thank in advance.
-- Sergio Souza Wireless Support