I washed my mail on my desktop computer (version 2012 1.20.0) and the email in the account that I am using with the beta on my iPad still show it. The Recycle bin on my PC shows the message in MW2012.
I closed the program using the "-" in the jiggly. When I restarted the beta, it still shows. I clicked "check" and it still shows and I can still view it.
Just to double check, I closed MW2012 and restarted it. The message still shows in the Recycle tab and not in the inbox. I even shut down & restarted my iPad. The message still shows.
I used my Outlook on my PC to get all of my email. I clicked "check" on my iPad and the message still appeared.
When I sent another message to that account from my PC, and clicked on check, the new message was there, but the washed mail was gone.