sure, try something like this: masquerade_classes=envelope_sender,envelope_recipient,header_sender,header_recipient masquerade_domains = host.$mydomain As far as LDAP with postfix, yes you can do that. I do that currently (most distros with postfix should have some sort of postfix-ldap package). Beware though, every lookup will generate an ldap query. You may want to use the proxy tables to limit the number of queries generated a little. Something like this: alias_maps = ldap:/etc/postfix/aliases.cf local_recipient_maps = proxy:ldap:/etc/postfix/local.cf virtual_maps = proxy:ldap:/etc/postfix/virtual.cf If you have a schema for mail in ldap already, it should be easy to set up. The hardest part for me is almost always coming up with a good schema to use. Jay -- Jay Kline http://www.slushpupie.com/