For Cutover Migration to Office 365 Process, the first step is to Verify your domain and then Connect Office 365 to Email System
How to Connect Office 365 to Email System for Cutover Migration Process?
Connect Office 365 to Email System Process is given here:
A relocation endpoint contains the settings and certifications expected to interface the on-premises server that has the letter drops you’re moving with Office 365.
The relocation endpoint likewise characterizes the quantity of post boxes to move at the same time. For a cutover movement, you’ll make an Outlook Anywhere relocation endpoint.
Go to the Exchange admin center.
In the Exchange admin center, go to Recipients > Migration.
Choose More > Migration endpoints.
On the Migration endpoints page, choose New .
On the Select the migration endpoint type page, choose Outlook Anywhere > Next.
On the Enter on-premises account credentials page, enter information in the following boxes:
(Email address, Account with privileges, Password of account with privileges)
If Office 365 successfully connects to the source server, the connection settings are displayed. Choose Next.
If the test connection to the source server isn’t successful, provide the following information.
(Exchange server, RPC proxy server)
On the Enter general information page, type a Migration endpoint name, for example, Test5-endpoint. Leave the other two boxes blank to use the default values.
Choose New to create the migration endpoint.
For more details, visit : www.office.com/setup