I am migrating 1600 mailboxes from Exchange 2007 to Exchange 2013, over 700 have moved fine, but 1 mailbox fails repeatedly.
When I run the migration in ecp it says the migration status is complete, but it also says that 0 mailboxes were synced, 0 were finalized and 0 failed. I also receive an email saying it completed successfully. The only thing, apart from the fact it says it worked when it didn't, is that the Total column changes from 1 to 0 while it is in Syncing status.
I'm confused, why is this not working? What do I need to do to fix it?