or download this
my $txtdata = "v=DKIM1; k=rsa; t=y;p=MIGfMA0GCSqGSIb3DQAFGQUAA4GNADCBi
+QKBgQDwWV9npEVjm10XoR1NIx174X/SR+BW8yd4RaXMk+pSDwNx0bFK8fPCXf7tLtFbjC
+mYldyhsrnrcloWPVlJkAy41xaTGUcXWpC2Onr/ScbkXa9cuREv4Fy4YmMpHoBKSHoE2JI
+8wBEe4oOoHPojT/b+HTNoZmxfkrYqk5eN5jnUewIDAQAB";
...
my $res = Net::DNS::Resolver->new;
$res->nameservers("ns.domain2.com");
my $reply = $res->send($update);