any mailbox covered by Defender needs a license:
Defender for Office 365 for Exchange Hybrid Setup
Khaled Ahmed Nafea
0
Reputation points
Dear Support,
I have Exchange Hybrid Setup and half of users migrated to Exchange online and half of users will keep hosted on Exchange on-premises and I want to change mail flow for inbound and outbound to go through Exchange Online using Exchange online protection and Defender for Office 365.
all Cloud users have Microsoft E3, and I planned to purchase Defender for Office 365 add-on Licenses, do need to have Defender for Office 365 Licenses for Exchange online users only or I need to consider the On-primes Exchange mailboxes?