I have preformed a staged migration from Exchange 2007 SP1 to Exchange Online.  I
have made all of my Exchange 2007 users MEUs.  My some 500 user mailboxes
and exchange database is taking up about 450 gigs on my exchange servers hard
drive.  What I want to do is delete all of those old emails within the
user accounts on the exchange 2007 server hopefully freeing up a lot of space.
 What is the best way to go about doing this?  I want to be able to
setup a new exchange server that does not require as much space on my virtual
server. The old exchange server is being used as a email relay and to manage
exchange online user attributes.  

Thanks for the guidance. 

• Edited by Eashton123 16 hours 18 minutes ago

run export-mailbox command move to pst and delete the content by date range.

Exporting to PST will have a back up of emails from date range and mailbox size will come down

Hope this helps

If there is no actual data within the EDB's that you care about simply dial-tone the databases i.e.

1. Dismount the databases

2. Delete the databases from disk

3. Mount the databases and exchange will squawk about the databases being missing and if you continue it will create new blank DB's

4. say yes, the new dbs are created and email flows as it was before