Resolution
goal
Is there a size limit for mailbox moves, an official limit or a practical one?
What is the recommended size limit for a mailbox move?
Are there size limitations to take into consideration for mailbox moves?
fact
Exchange Migrator 1.X
Exchange Migrator 2.X
Exchange Migrator 7.0
fix
There is no limitation for the size of a mailbox to be migrated as far as Exchange Migrator is concerned. However, please keep in mind that the larger the mailbox(es) is(are) or the larger the total number of individual email messages in a given mailbox(es) is(are), the longer the migration time will be. Mailboxes of excessive size or total number of email messages, may require seperate Projects to migrate so as not to impact performance.
note
There are known issues with migrating large mailboxes "hanging" the Exchange Migrator console. A ticket has been opened with Development to address these scenarios.