I was tweaking the “dev tools” VMWare image today in an effort to get mail routing working. I had dropped Postfix on the Red Hat Enterprise Linux 3 image but when it forwarded messages to our SMTP hub it acted like it was ignoring the “myorigin” config setting that told it to use only the domain name in the sender’s email address (rather than the fully-qualified host name).
Thanks to this thread, I was able to ascertain that it was probably a conflict with sendmail. Removing sendmail fixed the problem.
What was frustrating was that I got a couple of our Fedora Core 3 lab machines (non-virtual) working and they seemed to be able to coexist with sendmail just fine. I should have known to ignore that based on the different distro, sendmail, and postfix versions.