What you want cannot be done.
Most e-mail clients don't show it this way, but TB shows attachments this way. An image included in a message is always sent as an attachment. Same goes for html formatted stuff. E-mail is originally text based and with its display TB is true to that.
But like I said, other clients won't show it like that.
I'm just a user of The Bat! I don't work for Ritlabs.
Ohooo... Thanks so much for the reply...