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.
> Subject: Re: Changing the outgoing hostname in message headers > To: postfix-users@postfix.org > Date: Sat, 16 Nov 2013 08:02:29 -0500 > From: wie...@porcupine.org > > Paul C: > > Simon is correct, you must use multi instances, they are pretty simple to > > deal with, you run a few commands to create the instances, each one will > > have its own config directory with main.cf and master.cf, you can direct > > mail based on the incoming ip used to connect, inet_interfaces, but the > > software itself is only installed once, and all 3 instances will use the > > same core files, just config, queue and data directories are unique. If you > > are proficient with postfix, this will be a breeze for you. > > > > http://www.postfix.org/MULTI_INSTANCE_README.html > > If you need multiple personalities, that is he preferred approach > (especially considering that there are only three personalities). > > If is possible to kludge this with different SMTP clients in master.cf > (smtp-xxx . . . smtp -o myhostname=xxx -o smtp_bind_address=x.x.x.x) > and sender_dependent_transport_maps to select the outgoing smtp-xxx > client. But is a kludge, not a full multi-personality emulation. > > Wietse
