Import/Export from Outlook
When the migration is complete, removing your account from Outlook to set it back up with the new server details will
DELETE
your Outlook calendar. If you have an Outlook Calendar associated with the email account, you will need to back it up and then import it again once the new account is set up.
For further support doing this, please contact Outlook or a Microsoft Outlook IT specialist so you can ensure your calendar is migrated over without issue. If you need more time to do this, let us know immediately and we can give you more time to migrate over.
Outlook Import/Export Video Guide