If you create a batchfile with the following lines and modifiy the journalMBX value, this gives a quick easy way to check the mailbox total. AS opening outlook can take a while whent eh mbx is large.
Note This will only work for Exchange 2007 and does not split the total via message class, but is handy none the less and could be piped to a text file if you want to keep a running total.
@echo off
set journalMBX="EXCH_Journal"
PowerShell.exe -PSConsoleFile "C:\Program Files\Microsoft\Exchange Server\bin\exshell.psc1" -command "& {Get-User
'%journalMBX%' | Get-MailboxStatistics}
pause
