I got asked a question the other day on how to handle new User Mailbox creation in a Hybrid Deployment. I have seen some users go the wrong way and create the AD object and add the Attributes but they forget about the Exchange portion and then focus on adding the license in Office 365.
In Some scenarios this is correct but in a Hybrid Deployment any external email destined to the newly created mailbox will be stuck in the Exchange Undeliverable Message queue. To resolve this we need to create a Remote Mailbox for the newly created AD account.
We will Start by Opening the Exchange Management Console, then click expand Recipient Configuration and click on Mail Contact.
Next you will have to Click on New Remote Mailbox on the right hand side under the Action Menu.
Next you will have to follow the New Remote Mailbox Wizard.
Click on User Mailbox and then Next
Complete the User Information section and click Next
If you require and Archive Mailbox select “Add an Archive Mailbox” then click Next
Verify the New Remote Mailbox Configuration Summary and Click New
Click Fish on Completion
Next you can Open the Remote Mailbox Properties, Click on Email Addresses and verify that all Email Addresses are created correctly .
So now the On-premise Exchange Server is aware of the New Mailbox in Office 365.
The last step will be to kick of a Dir Sync and then assign a license to the new user.
Happy Emailing 🙂