So everything was working fine then we updated our System to the latest version . Now we have an issue configuring emails from our exchange server . The error i get in the logs is : A call to SSPI failed, see inner exception. ---> System.ComponentModel.Win32Exception: The client and server cannot communicate, because they do not possess a common algorithm ===> When using SSL/TLS 0008|Excpt|System.NotSupportedException: No compatible authentication mechanisms found. ---> When not using TLS/ SSL I had it configured without SSL/TLS in the past and it was working fine. Now after 15.5 update it does not. Any help is appreciated.