Thanks Quanah for your reply: Yes, it looks like im having the wrong idea: I 'just' need to check if a user have an entry at the People group (where the password is), and *also* if that user belongs to the MailUsers group (which contains the users able to use the mail system). BTW, im just playing with ldapsearch now, but this is intented to be a validation filter for a Zimbra instalation.
Then I think I would expect a filter of something like:(&(uid=gherzig)(memberOf=cn=MailUsers,ou=groups,o=Work)) with a base of "ou=people,o=work"
I.e., it would validate that there is an entry with uid "gherzig" in the person tree, and that the entry is a memberof the cn=mailusers group.
--Quanah -- Quanah Gibson-Mount Sr. Member of Technical Staff Zimbra, Inc A Division of VMware, Inc. -------------------- Zimbra :: the leader in open source messaging and collaboration