[Dovecot] Debian and dovecot

I have Debian 3.0 (woody) and installed the dovecot packages and it works ok with the default configuration. I want to change the default configuration, is any of this possible?

a) I don't want to create accounts for each user, can I have a mailboxes directory with the mailboxes of all the users? They are not many (10-15).

b) The authentication right now is done through PAM, the pam.d/dovecot file is:

auth           required    pam_unix_auth.so
account     required    pam_unix_acct.so
password  required    pam_unix_passwd.so
session      required    pam_unix_session.so

I want to authenticate against an SMB server, I added the following /etc/pam_smb.conf:

SPECTRON-MSIM
MAIN
MAIN    # documentation says I need 2 servers (only have one, is this

ok)

and changed the pam.d/dovecot to:

auth           required    pam_smb_auth.so
account     required    pam_smb_auth.so # there is no pam_smb_acct
password  required    pam_smb_auth.so # there is no pam_smb_passwd
session      required    pam_smb_auth.so # there is no pam_smb_session

and it doesn't work. I obviously did something wrong, but don't know what, and I found nothing that could help me on google. I have samba installed and it works so It's PAM that I'm configuring incorrectly.

Hope someone here can help me.

Fawzib Rojas