In theory, you can wrap it in the html tags for 'blink' which are <bl ink> at the front and close it with </b link> at the end...without the spaces of course (they wouldn't show up as text if I'd left them out)
<blink>BLINK</blink>
The recipient will have to have their options set to show htm coding, or it won't work.
I haven't tried it though, so it may not work....send yourself one to test it
EDIT.....leaving the spaces dint work...hit the quote button as if you were going to quote this post in a reply and you'll see the code in the quoted text though