Beispiel: info@mein_Domainname.de
<script language="JavaScript">
<!--
var name = "info";
var domain = "mein_Domainname.de";
document.write('<a href="mailto:' + name + '@' + domain + '" onFocus="if(this.blur)this.blur()">');
document.write(name + '@' + domain + '</a>');
// -->
</script>
die Ascii-Zeichen findest Du z.B. in selfhtml...