I received a call to advise that none of my clients Outlook clients could connect to Outlook.
After ruling out the usual suspects, I dug a little deeper, and found a number of these events in the System event logs on the mail server.
This was also
The fix was pretty straight forward.
On the mail server, run CMD as Administrator, and run the following commands.
netsh http show sslcert
Copy down the certhash and appid from 0.0.0.0:443
netsh http delete sslcert ipport=0.0.0.0:444
netsh http add sslcert ipport=0.0.0.0:444 certhash=<insert your copy here without the brackets> appid="Insert your copy here, including the " and {}."Once all that is done, everything should be working perfectly fine again.