Forum Discussion
Ethical Wall: Deployment And Maintenance
I would start with Exchange transport rules, see https://technet.microsoft.com/en-us/library/jj919238%28v=exchg.150%29.aspx?f=255&MSPPError=-2147217396.
You may also want to use DLP and IRM to evaluate content and enforce usage rights on files.
Dynamic AAD groups could be very helpful, providing you have appropriate attributes on the user accounts.
Thank you!
You are welcome. Another thing you may want to investigate are the controls to block external sharing to specific domains. I don't know how this would work if the users domain was enabled in the tenant, but it could be worth some testing.
see https://support.office.com/en-us/article/Restricted-Domains-Sharing-in-Office-365-SharePoint-Online-and-OneDrive-for-Business-5d7589cd-0997-4a00-a2ba-2320ec49c4e9?ui=en-US&rs=en-US&ad=US for the details.