I came in this morning to find email issues amongst dozens of my users here.
I personally was not affected. It turns out when I looked at each users settings (after verifying nothing wrong on the exchange) that their RPC over HTTP settings had changed.
The authentication type should be "BASIC" but had been changed to NTLM. When you select NTLM, it will set Outlook to connect via HTTPS only. Basic on the other hand will mutually authenticate from HTTP to HTTPS.
Has anyone else noticed this? I am thinking that an update has been applied and caused this. But I am baffled as to why it would change this personal setting? This is generally not setup but we use it here.
