I had just recently re-installed Ubuntu and a customer noticed that the from address was incorrect.  Research lead me to a missing /etc/pine.conf.

     Checking our other shell servers, it was missing on approximately half.  I also found configuration issues with postfix on several.

     These are all corrected and I have tested sending with mailx and alpine with incomplete to addresses (just the local username) on all of these machines and they are all now working properly.