Correct format for any messages through the mail gateway at default?

I was able to get past my prior apache problems by manually symlinking the perl module for modperl from modules available to modules active. However the main problem is that I am. not at all sure for the exact default syntax for mail and what to expect. Most of the examples are in the format of using an on machine default email account. I already have fetchmail and postfix setup to do basic work from gmail accounts however fetchmail is passing unformatted re-written email addresses from that account. i.e. [not actual]. how would I have to change the setup in the web configs to accept this and what format would it have to take.