SMIL language is used to create the presentation part to MMS messages. Only a small subset of a SMIL commands are being implemented to Nokia phones. Only way to have such a shapes is to create a image and include it to the message.
If you are sending a MMS message from your phone to some e-mail recipient, you just add the e-mail address to the recipient field. E-mail to phone from PC is different. You need to ask your local network operator if they offer a e-mail gateway.
1: The Vector Format that should be supported is called "Scalable Vector Graphics".
1. W3C Working Draft Recommendation: "Scalable Vector Graphics (SVG) 1.1 Specification", http://www.w3.org/TR/SVG11 , February 2002.
2. W3C Working Draft Recommendation: "SVG Mobile Specification", http://www.w3.org/TR/SVGMobile/, February 2002
You need to define the Type in you SMIL document and according to the spex, your job should be done.