Hello, You could use: Local.example.com. IN A 127.0.0.1 Example.com. IN MX 10 local.example.com. This way systems shouldn't deliver it at your system. What you did mention is something we don't allow our customers to do (if I am correct). With kind regards, Mark Scholten -----Original Message----- From: Eric J Esslinger [mailto:eesslinger@fpu-tn.com] Sent: dinsdag 15 december 2009 16:18 To: 'nanog@nanog.org' Subject: DNS question, null MX records I have a domain that exists solely to cname A records to another domain's websites. There is no MX server for that domain, there is no valid mail sent as from that domain. However when I hooked it up I immediately started getting bounces and spam traffic attemtping to connect to the cnamed A record, which has no inbound mail server (It's actually hitting the firewall in front of it). (The domain name is actually several years old and has been sitting without dns for a while) I found a reference to a null MX proposal, constructed so: example.com IN MX 0 . Question: Is this a valid dns construct or did the proposal die? I don't want to cause people problems but at the same time, I don't want any of this crap to even attempt to deliver on this domain to any of my servers. __________________________ Eric Esslinger Information Services Manager - Fayetteville Public Utilities http://www.fpu-tn.com/ (931)433-1522 ext 165 ________________________________ This message may contain confidential and/or proprietary information and is intended for the person/entity to whom it was originally addressed. Any use by others is strictly prohibited.