HI there,
First of all, I am not sure if I should post this here or on an IIS forum.
I have an Exchange 2013 server and an Application Request Routing (ARR) server that acts as a proxy to it. Traffic to and from the internet pass through the ARR server before coming to the Exchange server.
The ARR server is basically just an IIS server.
Emails to and from the ARR server pass through a spam filter found in the cloud.
We are moving to another cloud spam filter.
I have already configured the ARR server to send outgoing emails to the new spam filter and it is working.
However, incoming emails are a problem.
I am getting the following delivery failure:
Final-Recipient: rfc822;testuser@mydomain.com
Action: failed
Status: 5.7.1
Diagnostic-Code: smtp;530 5.7.1 Client was not authenticated
I checked on the internet and found that it is due to Anonymous being disabled on theDefault Frontend receive connector.
However, Anonymous is already enabled on the connector.
The weird thing is that on the SMTP server on IIS, I changed the OUTGOING smart host and it is affecting INCOMING emails. If I revert back to the original smart host, incoming emails start being delivered correctly.
Can anyone help?