Learn more about hybrid deployment sending transport servers
Applies to: Exchange Online, Exchange Server 2013
This feature of Exchange Server 2013 isn’t fully compatible with Office 365 operated by 21Vianet in China and some feature limitations may apply. For more information, see Learn about Office 365 operated by 21Vianet.
On the Sending Mailbox servers page, select one or more servers in your on-premises organization that have the Mailbox server role installed. The selection of multi-role servers is also supported. A multi-role server is a server that has both the Mailbox and Client Access server roles installed.
The on-premises Mailbox servers you select here will be configured with Send connectors by the Hybrid Configuration wizard to deliver secure mail to the Microsoft Exchange Online Protection service in your Office 365 tenant.