[Dovecot] Authentication userdb file / configuration help - newbie question...

[Zilon X]

Hi All,

     I need to configure Dovecot with a XMail server (
www.xmailserver.org ) - this server uses a userdb file with the
following format:

"domain"[TAB]"account"[TAB]"encrypted-passwd"[TAB]"account-id"[TAB]"account-dir"[TAB]"account-type"[NEWLINE]

How can authenticate Dovecot against this userdb file? Was anyone doing that?
Maybe, can I authenticate Dovecot using SMTP Auth?

Thank you for any help!