Thread:Project:Support desk/Email authentication broken following upgrade/reply

Just to add a bit more information on this - it seems that it is in fact all system email that have failed - user to user email and password reminders too. $wgEmailAuthentication is set to "true". Could it be a problem with $wgPasswordSender ? I had left it at the address generated during initial set up, but do I need to change it? If so, can I just set it to any email address, or does it need to be a specific system email address? (sorry for noob questions, I'm only an ameteur!)