Daily Archives: 24/03/2015

Office 365 tenant to tenant migrations. Some things you should know about

Published by:

Dan Patrascu-Baba

Partner Technical Consultant at Microsoft
Azure PaaS and dev consultant, working for Microsoft. Mostly dealing with Microsoft Azure services, ASP.Net Core, AngularJS, Javascript. Helping partners and customers to write good code and to architect their cloud and hybrid solutions.

With cloud adoption going at a fast pace, Office 365 tenant to tenant migrations are scenarios that IT pros have to face more and more often. When a company using Office 365 acquires another company that also uses Office 365, it is obvious that the resources have to be consolidated in a certain way. Being cloud-only organizations, the only choice is a tenant to tenant migration. As this process is pretty painful, I thought to blog about it and point out some things you should know about.

At first, we would have to migrate the users and mailboxes from one tenant to another, including the used mail domain, like domain.com. My recommendation is to start the verification process of the mail domain in the target tenant and to create the necessary DNS record to prove domain ownership. Sure, we won’t be able to completely verify the domain since it is still present on the source tenant, but by doing this we can make sure that the new DNS record will be appropriately propagated in DNS by the time we have removed it from the source tenant.  Continue reading