On Mon, 18 Sep 2006 17:57:43 +0200, Peter Dambier said:
It can make sense:
I am sending my mails mostly from lumbamba.peter-dambier.de (192.168.48.226) my router is krzach.peter-dambier.de (192.168.48.2) my mailer is echnaton.peter-dambier.de (192.168.48.228)
My traceroute looks ok although some of the hosts are RFC1918 If somebody looks into my email headers they find information that makes sense although they could not ping the hosts.
As long as you do not allow AXFR, nobody can see the information about RFC1918 hosts. So there is no risk.
Unless of course you're leaking it in Received: headers.. Or DNS requests across the public Internet (remember, we *started* with the question of having this stuff on a public-facing DNS server..).. Or all the other myriad ways this stuff tends to leak out. AXFR is the *least* of your problems.