NOTE: The CSV file for a migration batch can contain a maximum of 2,000 rows. This means that you are limited to migrating ...

NOTE: The CSV file for a migration batch can contain a maximum of 2,000 rows. This means that you are limited to migrating 2,000 mailboxes at a time. To migrate more than 2,000 mailboxes, create additional CSV files and use each file to create a new migration batch.