I am attempting to use powershell to gather emails that pertain to a certain subject, so that these correspondences might be turned over to a legal department. I am having a couple of issues here that I would like some assistance getting past.

I run the following command:

get-mailbox -Database "Mailbox Database" | 
Export-Mailbox -ContentKeywords "Keywords To Search" 
-TargetMailbox "sec_goat" 
-TargetFolder EmailSearch 
-StartDate "01/13/2011 12:01:00

This has pretty much done what I want, and returned a boat load of emails, however it has also flooded my inbox with hundreds of blank calendars and contact lists. I realize now I should have used the exclusion on these folders, as well as a test environment (which we don't have).

1.How can I clean up this script to not include all the blank folders, contacts and calendars that DO NOT match the keywords search?

2.How do I clean up hundreds of blank contact lists and calendars in my mailbox without right clicking and deleting each one?

EDIT: I edited the post to change the scope of the question. I think my focus is less on the legal perspective and more on the "How can I clean up my mess and make future archives less messy and painful?"