We're looking at upgrading to Exchange 2010.
We've just gone through the Pre-deployment Analyzer check and the numbers for the Databases seem far too large for what we have to work with. Currently the Exchange 2003 environment has 19 DBs across 3 Mailbox servers all less than 100 GB per DB.
Based on our average usage (6500 users, less than 50 emails per user per day, approx. 130KB per message), the Exchange 2010 Mailbox Calc. is giving us DB sizes of 190 GB per DB @ 90 DBs. That's insanely high for the storage we have to work with. We're looking at less than 4 TB to work with on the upgrade and the current total size of the mailboxes now is about 1.3TB at present.
Can anyone give any thought to a large scale mailbox DB configuration across 2-3 mailbox servers?