To migrate mailboxes from Outlook.com to Office 365, you need to use the IMAP migration method.
After you've added your users to Office 365, you can use Internet Message Access Protocol (IMAP) to migrate email for those users from their IMAP-enabled email servers.
In the Microsoft 365 admin center, go to Setup > Data migration to start migrating IMAP enabled emails. The email migrations page is pre-configured for migrations from Gmail, Outlook, Hotmail and Yahoo. You can also enter your own IMAP server name and connection parameters to migrate from an email service that is not listed.
Reference:
https://docs.microsoft.com/en-us/exchange/mailbox-migration/migrating-imap-mailboxes/imap-migration-in-the-admin-center

Project1: During Project1, the mailboxes of 100 users in the sales department will be moved to Microsoft 365.
Fabrikam does NOT plan to implement identity federation.
All users must be able to exchange email messages successfully during Project1 by using their current email address.
During Project1, some users will have mailboxes in Microsoft 365 and some users will have mailboxes in Exchange on-premises. To enable users to be able to exchange email messages successfully during Project1 by using their current email address, we'll need to configure hybrid Exchange.
A new way to migrate mailboxes in a hybrid Exchange configuration is to use the Microsoft 365 data migration service. The data migration service can migrate Exchange, SharePoint and OneDrive. Therefore, we need to start a data migration and click Exchange as the service to be migrated.
Reference:
https://docs.microsoft.com/en-us/fasttrack/O365-data-migration
https://docs.microsoft.com/en-us/exchange/hybrid-deployment/move-mailboxes This is a case study. Case studies are not timed separately. You can use as much exam time as you would like to complete each case. However, there may be additional case studies and sections on this exam. You must manage your time to ensure that you are able to complete all questions included on this exam in the time provided.
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Overview

Your devices use a service connection point (SCP) object during the registration to discover Azure AD tenant information. In your on-premises Active Directory instance, the SCP object for the hybrid Azure AD joined devices must exist in the configuration naming context partition of the computer's forest. There is only one configuration naming context per forest. In a multi-forest Active Directory configuration, the service connection point must exist in all forests that contain domain-joined computers.
Reference:
https://docs.microsoft.com/en-us/azure/active-directory/devices/hybrid-azuread-join-manual

During Project1, some users will have mailboxes in Microsoft 365 and some users will have mailboxes in Exchange on-premises. To enable users be able to exchange email messages successfully during Project1 by using their current email address, we'll need to configure hybrid Exchange.
To migrate mailboxes in a hybrid Exchange configuration, you use Exchange admin center perform Remote move migrations.
Reference:
https://docs.microsoft.com/en-us/exchange/hybrid-deployment/move-mailboxes