When I set up a small masqueraded private network, that is connected to Internet only by ppp link, I set up the domain for this network like 'whatever.loc'. Usually, I also build a DNS server, that is a master for whatever.loc, but also points to root servers on Internet. Sendmail is configured to relay whatever.loc domain, but when the queued messages are sent from it to 'real' SMTP server on Internet, the envelope address is rewritten to real one, i.e. instead of [EMAIL PROTECTED] the From: field will read [EMAIL PROTECTED] To do this, I wrote a set of rules for sendmail, but later I found, that this can be easilly done by masquerade_envelope macro in sendmail-m4.
Radim
