coded = "YK<Fj c. rtKxx bWTQj15tKxx.to5V"
key = "rfBU><k725QLPAx3WE9M1jdmHpwFJKhoyDGVbN0vIXRga48CsZcOzl@nT6uqYiteS"
shift=coded.length
plain=""
for (i=0; i<coded.length; i++){
    if (key.indexOf(coded.charAt(i))==-1){
        ltr=coded.charAt(i)
        plain+=(ltr)
    } else {
        ltr = (key.indexOf(coded.charAt(i))-shift+key.length) % key.length
        plain+=(key.charAt(ltr))
    }
}
document.write("<a href='mailto:"+plain+"'>Kevin M. Goess &lt;cpan@goess.org&gt;</a>")