This post will go over some of the many errors that occur when attempting to move a mailbox to Office 365. The error messages you see are discovered when showing the details of a failed migration and then clicking on a failed user in that migration.
Issues
1. “You can’t use the domain because it’s not an accepted domain for your organization”
Office 365 will not accept migration of a mailbox if that mailbox has an email alias that includes a domain that doesn’t exist in Office 365.…