Data Protection for Exchange uses the VSS method for backing up data.
Data Protection for Exchange tracks and stores mailbox location history, which is used to automate mailbox restore operations. This action causes a delay before each backup. In small or centralized Active Directory environment, the delay might be a few seconds or minutes. In large or geographically dispersed environments, the delay might take more time.
If you do not plan to use mailbox restore, you can safely disable mailbox history.