Are you meaning profile email or to an email address?
Profile mail is pretty easy, as you'd just enter the link to your profile mail using the "Cached Clickable Web Image" in this format.
Code:http://utherverse.com/email/Compose.aspx?to=memberIDnumber
Replace memberIDnumber with your member ID
As for regular email, that is a bit trickier. Since more and more people use a web client these days, it wouldn't be as easy to use a prop to kick them directly there. In that case, it is easier to just have the address printed somewhere for them to copy and paste.