You may have decided a few years ago to move your email, file sharing, and productivity apps to the cloud using Google Apps -- why manage all those servers and apps in your data center? But for productivity apps, Google Apps is not as richly featured as Microsoft Office. Now that Microsoft has its own cloud service for email, file sharing, and productivity apps -- Office 365 -- you may be well tempted to switch.
If you're moving from on-premises Exchange to Google Apps or Office 365, there's good documentation on how to migrate. But what about moving from one cloud to the other? It's not so obvious, as you don't have a local environment in place for recovery or staging.
Depending on your size and budget, you have two options: manual migration, where you handle the swap in-house, or third-party migration, where you use a tool. For smaller migrations and do-it-yourselfers, Office 365 offers a migration wizard for email, but it won't migrate contacts or calendars.
The manual migration method
If you plan on doing the migration yourself, Kanwal Khipple recommends several tweaks based on his own migration experience, such as increasing the Office 365 connection limits to your IMAP server (Gmail limits it to 15 simultaneous connections), shortening the DNS Time-to-Live setting on your MX record, and backing up and deleting any filters set up in Google Apps.
The first step is to create the mailboxes in Office 365, which you can do one at a time or in bulk using a CSV file. You also need to assign licenses to each user for Office 365. At this point, you probably want to switch the DNS MX records from Google Apps to Office 365, so no email is lost in the switch.
When you are ready to migrate email, use the Office 365 portal's Exchange email migration tool. It is available in several locations if you are an admin:
- In Outlook Web Access, go to the Manage My Organization settings and in Users & Groups go to the Email Migration tab.
- In Office 365's Exchange admin portal, go to the admin settings and click the link to Manage to go to the Manage My Organization settings.