What you are managing to do with your "exploit" is no different than the following:-

telnet mx.yahoo.com 25
mail from: [email protected]
rcpt to: [email protected]
data
Subject: Hey gorgeous
Since your exploit isn't an exploit at all and doesn't carry any security implications whatsoever the ******* I promised you on friday has been withdrawn on the grounds that you are lame

luv Brit
.
quit

Yet the message id points at the sify.net only