Blank mail sender when mail sent using phpbb on a MAC

[r6ual]

OK, I've tried and tried to find the right answer for my question, but am really new to the MAC/linux thing, so i MIGHT have already found the answer, but haven't relised it.

I've got phpBB installed on a MAC OS X box. Runs perfectly, mysql all working fine and dandy. The issue is that when an email notification is sent from the bb, when recieved, the originating sender is blank :( I've played around afair bit on Windows machines, and the send_from is all too easy, but the MAC/Linux evades me.

Can someone PLEASE tell me, where the sneaky little setting is, so I can put in the desired 'sent from' email address.

Thanks heaps in advance.