When you are prompted to confirm Cutover our Onboarding tool displays the number of profiles that will start connecting to new servers.
The list of important things to check before cutting over to the new servers:
- MX records. Make sure they point to the new mail servers and have fully propagated.
- Mailbox Data. Log in to Webmail at owa.msoutlookonline.net for a couple of mailboxes and make sure the mailbox data is present there as expected.
- Outlook profiles are pre-configured to connect to new servers.
After cutover the new servers are used to send and receive mail.