Remember the days when you could open ESM click on the mail store and see all the mailbox sizes? then you could sort them with a click and know which users to go have a discussion with about mail usage? Where did that go in Exchange 2010\2007?
You can use powershell to gather all that info and export it to a CSV
Get-MailboxStatistics | sort-object totalitemsize -Descending | select-object displayname, itemcount, totalitemsize | Export-Csv -path c:\mboxStats.csv
Or if you want the GUI back
Glen Scales Developed a very cool powershell script that gives you a GUI for mailbox sizes
My only gripe is that he thought of it first
Great script man!