I'm looking for some pointers on what fields in the sendmail.cf file need to be modified to allow sendmail to masquerade emails.

For example, I want the machine to change outgoing emails to user@mydomain.com instead of user@mycomp.mydomain.com. I'm setting up Bugzilla and whenever I try to send emails through it they're rejected by the real mail server saying "domain of sender does not exist, root@localhost".

I've looked through the sendmail website and most of their info is based on modifying the sendmail.mc file and regenerating the config file, more work than I want to take on unless absolutly necessary.

Does anyone have a handy guide available on what needs to be modified in the sendmail.cf file to set this up?

This should help.

http://www.sendmail.org/m4/masquerading.html

I do had this problem and recreated sendmail.cf a hundred times. Not sure why but commenting out this line fixed my problem

dnl EXPOSED_USER(`root')dnl


Is supposed to only apply to root user, but in my case it was for all users.