Nov 07 2016 09:42 AM
Nov 12 2016 06:13 AM
I would start with Exchange transport rules, see https://technet.microsoft.com/en-us/library/jj919238%28v=exchg.150%29.aspx?f=255&MSPPError=-21472173....
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.
Nov 14 2016 07:11 AM
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.
Nov 14 2016 10:44 AM