Strange. This works for me:

use WWW::Mechanize;
$mech = WWW::Mechanize->new();
$mech->get("http://www.aaaedm.com/contact.htm");
print $mech->find_link(url_regex => qr/^mailto:/)
           ->url,
      "\n";
[download]

Prints:mailto:info@aaaedm.com