Exchange Mailbox data movement operations are constrained by the Microsoft MAPI API which limits data movement operations to an average of 2GB per hour per stream. This mode of data movement actually logs into each mailbox and scans each piece of mail as it is delivered to the Inbox.
You can improve the performance of data movement operations by creating multiple subclients. This will enable parallel data movement operations. However, the cumulative throughput of the Exchange server may decrease if sufficient system resources are not available. Therefore create user-defined subclients to divide mailbox backups into groups based on specific criteria. For more information, refer to Grouping Mailboxes Into User-Defined Subclients.
Last modified: 8/10/2018 3:28:27 PM