Question : e-discovery and HR Auditing for Exchange 2007 environment

I have an Exchange 2007 SP1 environment with a single mail store and 400 mailboxes.  HR and Legal would like to review emails from certain users.  I need to be able to give them access to the users email without the user knowing (i.e. I need to be sure emails dont show up as read, read receipts arent sent automatically etc.)

The legal department would also like for me to find ALL emails destined to or originating from a specific domain (obviously as part of e-discovery for a pending lawsuit).  

Is there any way to accomplish these 2 tasks without spending any money on a 3rd party app?

Thanks in advance for any help.

-B

Answer : e-discovery and HR Auditing for Exchange 2007 environment

You can export to pst using EXMerge or look at this post

http://www.experts-exchange.com/Software/Server_Software/Email_Servers/Exchange/Q_24446865.html