Bypassing Office 365
By Microsoft's own admission, Office 365 can be problematic when trying to access Office 365 services through Filtering Software/Proxies. For this, they have a provided a list of URLs/IPs that need to be bypassed in order for the services to work correctly. This list can be found at https://support.office.com/en-us/article/Office-365-URLs-and-IP-address-ranges-8548a211-3fe7-47cb-abb1-355ea5aa88a2?ui=en-US&rs=en-US&ad=US
As there are hundreds of URLs needing to be bypassed, we have also provided a condensed list in a USS friendly format. The URLs below act as wildcards, so will bypass entire domains, and not the exact subdomains provided by Microsoft. You can use this at your own discretion, but it offers a far smaller list for you to work with and with the same effectiveness of the list provided by Microsoft.
To begin, visit your USS Dashboard and click Products ⟶ Web Security ⟶ Bypass. Click to create a new Category. Give it a sensible name, like "Office 365".
For each of the URLs in the list below, click to add a new Pattern to the Category you just created. Set the Bypass Type to "Bypass Destination Domain Completely", and set the Pattern to the URL.
Microsoft lists the following URLs as optional:
Once you've added all of these Bypasses, they need to be enabled. Click Web Security ⟶ Agent Configuration, and choose a Configuration Profile. Click Bypass Categories and enable all of the Bypasses you created above. Finally, click .