I have no idea if this will work, but you might be able to do this server-side.
This allows you to replace @ with AT, . with DOT, and insert ADDRESS anywhere you feel like it.
$address = $_GET['address'];
$address = str_replace("ADDRESS", "", $address);
$address = str_replace("AT", "@", $address);
$address = str_replace("DOT", ".", $address);
header("Location: mailto:" . $address);
If you don't have a server-side language, you can use this one I set up.
Replacing the address with yours, of course.
Clever people (mwinter ): will this work?