Hello, We're planning a mail migration to Exchange 2010. Avg. mailbox sizes ar 1 GB. I'm trying to determine how much total WAN bandwidth will be required for post migration .OST download. For example, My remote office has a 3 Mb MPLS link to the Exchange servers and I have 500 migrated users with 1000 MB mailboxes. When all those users show up the next morning and log in, they'll all be downloading their .OST file at the same time and saturating the WAN link (500 MB of OST download). I'm looking for a WAN throttling policy or a best practice for how this problem is best handled. Staggering migrations is not really an option and I have limited bandwidth increasing potential. Thanks