Part 1. Configuring Sendmail on Solaris 10
Part 2. Configuring Sendmail to Masquerade Your Messages
Part 3. Configuring Sendmail to Relay Messages to Another Server
Part 4. Configuring Sendmail to Relay Messages from Other Servers
Sendmail MasqueradingNow that you've got your Sendmail up and running it's time to do some tweaking. If you try and send mail from your host, you'll notice that messages are sent from an address such as firstname.lastname@example.org. That's not probably what you want (that address isn't probably even reachable from the outside) and you'd rather like: email@example.com. Fine, that feature is called masquerading. To masquerade outgoing mail you can use the MASQUERADE_AS and MASQUERADE_DOMAIN macros, as in the following example:
VERSIONID(`@(#)sendmail.mc 1.11 (Sun) 06/21/04')
R$* < @ $* .$m. > $* $#esmtp $@ $2.$m $: $1 < @ $2.$m. > $3
Restart your sendmail and the job is done.