Setting Unique ringtones for notifications

I am trying to assign various ringtones to each of my emails on my Droid X and have found that since I have a common mailbox that it will not set one sound for each email within the main messaging box. Is there a way to assign a specific and unique ringtone to each email within the common messaging? It seems like whatever I set as the most recent email ringtone is the tone for all of the accounts.