diff -Nur Mail-SpamAssassin-3.4.1.orig/lib/Mail/SpamAssassin/DnsResolver.pm Mail-SpamAssassin-3.4.1/lib/Mail/SpamAssassin/DnsResolver.pm

--- Mail-SpamAssassin-3.4.1.orig/lib/Mail/SpamAssassin/DnsResolver.pm	2015-04-28 13:56:49.000000000 -0600

+++ Mail-SpamAssassin-3.4.1/lib/Mail/SpamAssassin/DnsResolver.pm	2016-06-11 13:55:15.380517343 -0600

@@ -592,6 +592,8 @@

   };

   if ($packet) {

+    # RD flag needs to be set explicitly since Net::DNS 1.01, Bug 7223	

+    $packet->header->rd(1);

   # my $udp_payload_size = $self->{res}->udppacketsize;

     my $udp_payload_size = $self->{conf}->{dns_options}->{edns};

     if ($udp_payload_size && $udp_payload_size > 512) {