I have a RH server that I renamed a few days ago from XXXX to YYYY. Previously email sent from the server would be sent from firstname.lastname@example.org. After using hostname to rename the server, they now appear as coming from email@example.com. That changing the hostname causes this issue makes me believe there was something using a search pattern on emails to find xxxx.network.int and renaming that to @domain.com. If not, the same domain should have continued being used. Unfortunately I'm very new to linux and am having trouble finding where this renaming could take place.
I've looked in /etc/mail/sendmail.mc and there's nothing in there that seems to fit (likewise unless I'm doing it wrong, MASQUERADE_AS(`domain.com')dnl as suggested at http://www.cyberciti.biz/tips/sendmail-masquerading-configuration-howto.html has no effect.) Trying to find information on this subject with whatever keywords I use turns up plenty of information, but nothing that quite fits this issue. I'm sure this is just a problem caused by my unfamiliarity with Linux, however.
Any suggestions on where I need to go to resolve this issue?