[Dovecot] How to configure auth_userdb and auth_passwd?

[Mirko Schulze]

Hi!

i want to configure dovecot to use a modified passwdfile. A linie in 
this file looks like this: "username: <TAB> crypted_password"

how i have to use the auth_userdb and auth_passwd command?
Now i have:
auth_userdb = passwd-file /path/file
auth_passwd = passwd-file /path/file (same file)

dovecot is starting normaly (i think) but a authentification test via 
telnet doesnt work.

Any suggestions?
Thanx a lot.
Mirko