[Dovecot] questions about ldap auth

[Gerardo Herzig]

Hi all. I have a couple of questions. ANY of those will solve mi
situation.

1) 'Complex' LDAP validation:
I need to validate a user in the 2 step authentication / authorizacion
mech.

The 'users' (with the password) are in
ou=Person,o=Work

the group which contains the mail users is in
cn=MailUsers,ou=Groups,o=Work

Can dovecot make such a thing? Cause im not shure if i can make this in
a single ldap filter.

2) If not...
2.1) Does dovecot accept more than 1 ldap filter for authenticating?
2.2) Does dovecot accept an arbitrary program for authentication?

Well, that's all for now. Thanks!
Gerardo