Cutover Migration – a classic approach to migration. Exchange 2013 is the last on-premises Exchange version that allows this type of mailbox move. In short, it allows you to move all mailbox content in one hop. It cannot be performed if you have more than 2000 mailboxes, but as this Microsoft’s article suggests, “due to length of time it takes to create and migrate 2000 users, it is more reasonable to migrate 150 users or fewer.”