This article outlines the complete task flow for migrating mailboxes from Hosted and On-Premises Exchange servers (versions 2007 and later) to Office 365.
We strongly recommend that you use HealthCheck for Office 365 to check ahead of time to see if end user hardware and software is compatible with Office 365. HealthCheck for Office 365 is a free utility.
Preparing the Source
Preparing the Destination
Create A Project
The following options are most valuable for Exchange to Office 365 migration scenario:
- Set to use impersonation at the Source. Checkmark the Use impersonation at Source box.
- Set to use impersonation at the Destination. Checkmark the Use impersonation at Destination box.
Read the How do I migrate to Exchange or Office 365 using impersonation? article for more information.
- Set Maximum concurrent migrations. To be very safe, we recommend initially setting this to 5. This means that when all mailboxes are selected and the migration begins, only the first five (5) mailboxes in the list will be migrated (using parallel processing), and then when the first of the five (5) completes, the next in the list will begin migrating, and so on down the list, through to completion of all mailboxes. If the Source server has enough server resources, set this parameter based on the bandwidth guideline of three (3) mailboxes per 1Mbps of bandwidth. Therefore, for example, if there is a 10Mbps connection, we recommend that the maximum concurrent migrations parameter be set to 30.