Been assisting with one issue recently and came up with the following cmdlet.
Hey-hey, glorious PowerShell!
get-mailboxstatistics | where-object {$_.disconnectdate -ne $null} | Select DisplayName,@{Name="TotalItemSize(KB)";Expression={$_.TotalItemSize.Value.ToKB()}} | Export-Csv c:\temp\mbx.csv | foreach {$_.length=($_.length)/1024/1024/1024; $_}
The output is really straightforward.
