We have SBS 2011 Pro running Exchange 2010 SP1. Last weekend we installed the Exchange Rollup 8 update and since then we are not receiving inbound email to our exchange server. This is the error being received when external users send us test emails
530 SMTP authentication is required. (state 13).
I assume the update might have changed a settings on the default receive connector in the transport hub but I am not sure exactly what the default settings should be for Authentication\Permissions or how else I can urgently fix this problem.
I would be very grateful of your help as we urgently need our email backup.
Many thanks
Murray