Exchange 2013 CU8
Windows Server 2012 R2 Standard
Here's the situation, an email is sent to a mailbox configured to forward to a MailContact with an external email address. The email bounces when attempting to route to the external email address with a ‘5.7.1 Client does not have permission to send as this this sender' error. I've managed Exchange 2010 in depth and configured forwarding to MailContacts many times without a problem. Has something changed with 2013?