@Paul_Warnagiris
We have a new feature in R80.20 that will help you out. We call them "Updatable Objects."
This is our only approach that will work to Reliably Categorize, and Detect O365 applications, currently.
On versions before R80.20, customers who wish to restrict access to the Office 365 services, based on IP Addresses, had to maintain a Network Group object that contains the relevant Network objects provided by Microsoft. The customers keep updating this object manually upon Microsoft updates and have to install policy after every change.
Please review the following SK articles for more info:
sk135572
sk131852