( $domain ) = $email =~ /\@([^\@]+)$/;

##</code><code>##

$email =~ s/(?:\@[\040\t]*(?:(?:[^(\040)<>@,;:"\\\[\]\000-\037\x80-\xff]|(?:\[(\040)<>@,;:"\\\[\]\000-\037\x80-\xff]))+(?!(?:[^(\040)<>@,;:"\\\[\]\000-\037\x80-\xff]|(?:\[(\040)<>@,;:"\\\[\]\000-\037\x80-\xff])))|\[(?:[^\\\x80-\xff\n\015\[\]]|\\[^\x80-\xff])*\])[\040\t]*(?:\([^\\\x80-\xff\n\015()]*(?:(?:\\[^\x80-\xff]|\([^\\\x80-\xff\n\015()]*(?:\\[^\x80-\xff][^\\\x80-\xff\n\015()]*)*\))[^\\\x80-\xff\n\015()]*)*\)[\040\t]*)*(?:\.[\040\t]*(?:\([^\\\x80-\xff\n\015()]*(?:(?:\\[^\x80-\xff]|\([^\\\x80-\xff\n\015()]*(?:\\[^\x80-\xff][^\\\x80-\xff\n\015()]*)*\))[^\\\x80-\xff\n\015()]*)*\)[\040\t]*)*(?:(?:[^(\040)<>@,;:"\\\[\]\000-\037\x80-\xff]|(?:\[(\040)<>@,;:"\\\[\]\000-\037\x80-\xff]))+(?!(?:[^(\040)<>@,;:"\\\[\]\000-\037\x80-\xff]|(?:\[(\040)<>@,;:"\\\[\]\000-\037\x80-\xff])))|\[(?:[^\\\x80-\xff\n\015\[\]]|\\[^\x80-\xff])*\])[\040\t]*(?:\([^\\\x80-\xff\n\015()]*(?:(?:\\[^\x80-\xff]|\([^\\\x80-\xff\n\015()]*(?:\\[^\x80-\xff][^\\\x80-\xff\n\015()]*)*\))[^\\\x80-\xff\n\015()]*)*\)[\040\t]*)*)*)$//;