If you try to send email using SMTP and get an NDR with a status of "5.7.1 Client does not have permission to send as this sender", then open the Exchange System Manager, and go through each mailbox and check that the Send As permission has been granted to NT AUTHORITY\SELF. That should fix the problem.
Exch2007 5.7.1 Client does not have permission...
Posted - September 22 2010 : 13:56:56
