Do you want do migrate mailbox in the way of hybrid migration? If so, in most cases, users don't need to re-create the configuration file as AndyDavid said. It is same as migrating mailboxes between databases on Exchange on-premises.
If you migrate mailboxes in the way of Cutover or Express migration which will create a new mailbox on Exchange online. You could joined your computer into Azure AD, then login computer with Office 365 account. After that, you will could configure Outlook with the login account automatically.
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