We're using Postfix 2.1.5 on an old Debian 5 Linux system as an
incoming, but not outgoing mail server. (We host several domains on
our server and don't want the mail headers for outgoing mail from (say)
CompanyA.com to say that they originated from a hostname that might be
CompanyB.com, CompanyC.
Thank you, men. I confess that my Postfix skills weren't up to handling
multiple instances or master.cf hacking, but we did have another domain sitting
idle which now serves as the bland mailserver hostname. Its presence in the
mail headers won't cause problems for any of the three companies.
