When using the newer streaming installers for Office 365 and Microsoft Office Online, you may encounter that install fails, that it cannot install or it cannot update Office.
This can be due to Sophos UTM Web Filtering protection, it doesn’t like that traffic is being intercepted (Transparent proxy).
Luckily you can make an exception for this in the UTM:
This is the regex code added in the “Target Domains” window:
Press save and it will work right away 🙂
P.S. The same regex code can be used for exceptions in Sophos XG firewall also. Just add it a little different, like this: ^([A-Za-z0-9.-]*\.)?officecdn\.microsoft\.com\.edgesuite\.net/