I found a script a few months ago that generated a CSV report of mailbox size, which included the Mailbox Name (usually the user’s name), size in Kbytes, number of items, which server it’s on, etc. This was very helpful, but I wanted to see which department within the company used the most space on the mail server, and the department wasn’t one of the pieces of data included in the report. It took a while but I figured out how to do LDAP lookups in vbscript and was able to add that info, so the report now has the user’s department, office location, and quota limit in it as well as the other fields. This makes it very easy to do a PivotChart in Excel to generate a pie chart of the size by department. The script is attached – change the extension to .vbs to run it. You’ll need to plug in your Exchange server and domain controller where the placeholders currently are.