Enabling/Creating a Mailbox on Exchange Online in a Hybrid Configuration (ADFS)
Considerations:
- Retention policy must be applied on the Exchange Online instead of against the on-premises AD object.
Use the New-RemoteMailbox cmdlet to create a mail user in the on-premises AD and also create an associated mailbox in Exchange Online.
Enable-Remote Mailbox is for an existing AD user.
- remoteRoutingAddress needs to be specified to point to cloud
- Forwarding would be set on the cloud mailbox using the cloud connection
References: