we are perfoming a double-hop migration from Exc 2003 to Exc 2010 to Exc 2013.
Location 1: Exchange 2003 on-premise and 2003 DC on-premise. Exchange 2003 DB is 200GB. Bandwith: 2/2Mbps.
Location 2: Head Quarters - bandwidth: T1
Location 3: New DC (2012 r2) and future Exc 2013 server installed at a COLO.
All 3 locations are interconnected via MPLS/VPNs. They can all talk to each other.
Since we have to do a double-hop migration and the bandwidth is terrible at the office where they physical 2003 exc server is setup, we need to find a solution to migrate smoothly.
Would it make more sense to export PST's and import PST's into users' Outlook clients (or server if there is a way).
If we had to do it this way, would we be able to migrate exchange to the new server WITHOUT the user's databases? In other words, can they have temporary blank mailboxes meanwhile we import PST's into their accounts locally at Location 2 or 3?
Or should we setup something called legacy server so 2003 and 2010 can co-exist for a while until the migration completes. Ran some calculations and could take up to 10-15 days at full bandwith. So that really means 30 days to play it safe.
I really would prefer to do more work upfront and be done with it, then have to wait weeks for it to migrate mailboxes over the WAN.