Identify Users and Mailboxes to be Migrated
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1h 10m

Microsoft 365 represents a combination of Office 365, Windows 10 and Enterprise Mobility offerings – providing the most complete set of SaaS technologies that Microsoft has to offer. With Microsoft 365, organizations can deploy a complete solution encompassing both devices and applications, along with applying security and compliance policies to protect the entire suite.

This course will help you as you plan your migration of users and data to Microsoft 365, including planning your identity and authentication solution, and the on-premises infrastructure needed to support your migration. We’ll also help you understand and identify your business requirements and use cases, to help drive your decision-making process when planning to transition your infrastructure to the Microsoft cloud. We’ll spend some time focusing on networking and discuss some of the networking decisions that need to be made to ensure an optimal migration experience, as well as the best experience for your users after migration.

This course will also help you to identify which data needs to be migrated to the cloud, and what the best migration method will be based on your scenario – we’re also going to cover the different types of user identities, how your users will authenticate, and how that’s going to affect your migration planning.

In addition to talking about these different components, we’re also going to run through a few demos – showing you some of the practical steps involved, along with some tips and tricks we’ve picked up along the way. 

Learning Objectives

By the end of this course, you should be able to:

  • Plan a Microsoft 365 Implementation, including the supporting infrastructure
  • Plan your identity and authentication solution, both on-premises and in the cloud
  • Identify your users, data, and mailboxes to be migrated to Microsoft 365
  • Plan the migration of your groups and user data to Microsoft 365

Intended Audience

This course is intended for people who:

  • Want to become a Microsoft 365 administrator
  • Are preparing to take the Microsoft’s MS-100 exam 


To get the most from this course, you should have a general understanding of networking & server administration as well as IT fundamentals such as DNS, Active Directory and PowerShell.


Now that we've talked about the different types of mailbox migrations, let's talk a bit about how you would select your users from migration batches and factors to keep in mind so that your migrations go as smoothly as possible. 

First would be permissions. An Exchange Online hybrid migration supports several permission or delegate scenarios cross premises such as Full Access and Send on Behalf of. Send-As permissions are not supported cross premises, but if you re-apply those permissions manually after migration, send-as will still work. However, what's not supported cross premises is automatic mapping of mailboxes that you have full access to and delegate folder permissions. You can still open a shared mailbox manually and folder permissions can be reapplied, but overall, it's a great idea to migrate teams of users or business units together. You can end up in a bit of a permission spiral when planning your migrations if you're constantly trying to figure out who has access to which mailbox and end up with this giant spider's web of access and permissions. 

Far better to sit down and map out some clear scenarios that you want to ensure are going to work the best during and after migration, such as executives and their admin assistants. Migrate these types of delegates together for the best experience. Other markers you can use would be business units or departments. Generally, you'll find that these teams and business units are collaborating together on shared mailboxes or shared resources, and they will work best if they are migrated all at the same time or within a short time period of each other. You also might want to migrate entire office or branch locations at the same time. You can really use any logical group of users you want. Just be mindful of permissions and delegates as you go and your users will have a smooth migration experience.

About the Author

Jeremy Dahl is a Senior Technology Consultant who has spent the last 8 years focusing on Microsoft 365 technologies and has been an Office 365 MVP for the last 6 years. Jeremy is a self-proclaimed cloud addict who architects technology solutions that combine cloud technologies with on-premises solutions, allowing organizations to make the most of their existing infrastructure while still taking full advantage of the agility and scalability of what the cloud has to offer.

Jeremy can be found blogging about Microsoft 365 technologies on his website,, and evangelizing the Microsoft cloud on Twitter.