I believe you can do this with quarantine. The spool on my system to get to this is on a different drive so be aware of this. If you have a lot of traffic on your server enabling quarantine will fill up quickly. I make a UNC connection to the folder with "GREPWIN" and I put the destination address in the text search. Send the email and search the folder, constantly refreshing grepwin until I get the eml and hdr file. I believe these are the steps for enabling quarantine.

 

I hope this helps.