I just recieved a phone call saying that an external user cannot send email to users here. the error that they recieve is - "550 5.7.1 sender id (pra) not permitted" the current setup is symantec mail security gateway ----------> exchange 2003 sp2 server i configured exchange with the ip of the perimeter server, my question is what isa PRA (i know its purported responsible address, what exactly is that?) and why is his emails being blocked? my guess is that the headers are not matching up? help! thanks, - gabe
