We are having an issue that started Last Friday. When Windows 7 (only) machines are connected to our internal network they can not open Outlook (it hangs). If that same machine jumps onto an external network its fine. Also users can run Outlook in Office 365 no problem. We think some update hit our domain controllers on Friday causing the issue but we have not been able to fix the issue. We have tried giving user admin rights, disabling our Sophos antivirus but nothing is working. All windows 10 machines are fine.