I'm not to sure I understand what you are saying ....sorry , I'm french....nobody's perfect ;-)
On my phone when I want to send a message , I put in the name of my contact . When putting phone nuraber :if it shows in blue that means my contact has an iPhone (With iOS5) , if green then the message will go as a regular SMS.
With email address ,the same color code applies . If blue ☞ iMessage . If green ☞ MMS .
