We were lucky to have a good AV in place when we got hit with the most recent 0 day exploit for the web shell. We caught it immediately and in the end decided to completely rebuild our server to CU21 w/ the latest SU. We ran into some issues with IIS failing to install correctly and had to pay MS to help us fix it.
Now we have an odd issue where some 3rd party devices can't email when authenticating. Doesn't matter if we use TLS, SSL, or none, they won't work. Since we run an old AS400 and RPG doesn't support current standards I decided to piggy back on my AS400 Anon Receive connector and allow these devices to email by using IP restrictions and our noreply account as the reply address. This worked for most devices.
The problem is that I have one last device I can't get working. It's a really old Generator Adapter that only runs on old installs of IE/silverlight (we have this setup for just this purpose). I can't get the adapter to send emails either via auth or anonymously like our other other devices. I also can't find any error messages in the Generator Adapter, Exchange Logs, Event Viewer Logs, or Message Tracking Logs. What I really need is to just find the error message to see if I can fix this. Does anyone know of a good way to find the error between client and server? Or is there a way to tell what rule a IP is hitting when it tries to email? I'm ok with fixing auth or using anon rules by IP but neither seem to work on this old thing.