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

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!