That's not gonna work, davisagli.
As tye already pointed out, a well-written robot will follow your redirect and eventually harvest the valid mailto: URL which is returned by your script. For example, the following snippet catches the email address:

my $req = new HTTP::Request('GET', $url);
my $res = LWP::UserAgent=>new->request($req);
if ($res->is_success) {
    # do something here
} elsif ($res->code == RC_BAD_REQUEST) {
    print "URL: ${\$res->previous->headers->{location}}\n";
} else {
    # do something else
}
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