Just make a link...
http://login.passport.com/login.asp?id=2&ru=http%3A%2F%2Fhotmail.msn.com%2Fcgi-bin%2Fcompose%3Fcurmbox%3DF000000001%26a%3D5923bd6c1845c649c283ccfc41212975%26mheader%3Dto%26login%3D%26mheader%3Dto%26address%3Derwin.v3x8srdi4czwdwzt7ur726%2540zend.nu%26curmbox%3DACTIVE
If you parse this url via [man]urldecode[/man], you should be able to figure out how to get your email address in there.