In this post, I document the process of migrating mailboxes from Exchange 2013 on-premise to Exchange Online when in the Hybrid Configuration. This assumes that you have already performed the following steps:
- Office 365 tenant created
- Azure AD Sync setup
- Exchange Hybrid Configuration Setup
There are other migration methods (cutover, staged). However, in this post, I focus upon the Hybrid scenario with remote move using the MRS.
Review Technet Documentation on Migration
- https://technet.microsoft.com/en-us/library/dn592150(v=exchg.150).aspx ; Best Practices
- https://technet.microsoft.com/en-us/library/jj874458(v=exchg.150).aspx ; Creating Migration Endpoints
Email Migration Process
- In O365 Admin Center, check that the user’s doesn’t have a mailbox on o365
- Check the mailbox and contacts in O365
- Go to the Migration tab and create a new Migration Batch (hit +) and “Migrate To Exchange Online”
- Add the users to migrate who are mail-enabled in O365 and have mailboxes on-premises.
- Specify the Migration Endpoint. This needs to be setup before running the Migration Batch.
- Specify the batchname.
- Specify whether to automatically complete the migration. I am going to manually specify it so that I can control when the cutover happens.
- Migration synchronization process begins.
- Once the synchronization process is complete and when you’re ready to move the user to Office 365, start the “Completing the Migration Batch” process.
- When its completed, the user’s mailbox is now on Exchange Online in Office 365.
If you check the Exchange server on-premises, you’ll notice that the mailbox type for the user is now “Office 365”.
- In Office 365, if you go to Recipients > Mailboxes, you’ll see the users with mailboxes.
- In Office 365, if you go to the Recipients > Contacts, you’ll notice that the users that you migrated will no longer have MailUser objects listed there.
- To allow the user to access their mailbox in Office 365, you’ll need to add the Exchange Online license to the user.
- If you check in remote powershell to Office 365, you’ll notice by running get-user and get-mailbox that the user’s mailbox is now on Office 365 as we saw in the web UI.