Deleting user in AD

Sometimes when we try to delete a user in AD it'll give us the message:

Object <name> contains other objects. Are you sure you want to delete object "name" and all of the objects it contains?

This is usually caused by a mobile phone which is syncing with the account. To fix this we go to the user's mailbox in Exchange 2010 EMC, right click the mailbox and manage mobile devices. Then we delete every partnership listed. Once that's done we can delete the user with the annoying message.