EdgeSync producing 5.7.1 "Client was not authenticated"

Hi guys,

I have an Exchange 2007 and 2013 coexistance scenario. I have an Edge Transport, with FPE, and a HT/CAS in Exchange 2007 with SP3 and CU1.

In Exchange 2013 I have 2 CAS and 2 MBX.

Just now I am running tests from my Edge server, checking delivery to a Mailbox Server in 2013 using Telnet. However, I am seeing in the message delivery logs 5.7.1 "Client was not authenticated" when the message is attempted to be sent to the Mailbox server.

EdgeSync is apparently working fine.

Thanks for your help!