Your virtual_alias_maps is incorrect.
virtual_alias_maps =
proxy:ldap:/etc/postfix/ldap/virtual_alias_maps.cf,
proxy:ldap:/etc/postfix/ldap/virtual_group_maps.cf,
proxy:ldap:/etc/postfix/ldap/sender_login_maps.cf,
proxy:ldap:/etc/postfix/ldap/catchall_maps.cf
The correct one should be:
virtual_alias_maps =
proxy:ldap:/etc/postfix/ldap/virtual_alias_maps.cf,
proxy:ldap:/etc/postfix/ldap/virtual_group_maps.cf,
proxy:ldap:/etc/postfix/ldap/virtual_group_members_maps.cf,
proxy:ldap:/etc/postfix/ldap/catchall_maps.cf
This change is mentioned in upgrade tutorial of 0.8.0 -> 0.8.1:
http://iredmail.org/wiki/index.php?titl … ice.3Dsmtp