[67292] in North American Network Operators' Group
question on ptr rr
daemon@ATHENA.MIT.EDU (garrett.allen@comcast.net)
Sat Feb 7 06:26:19 2004
From: garrett.allen@comcast.net
To: nanog@merit.edu
Date: Sat, 07 Feb 2004 11:25:39 +0000
Errors-To: owner-nanog-outgoing@merit.edu
this may be deemed off topic - if so apologies in advance. however i respect many of the opinions i see here so thought i would take a chance and ask.
we are a stub network, injesting about 30k emails daily. about a year ago we implemented a spam filtering product. it works well. recently we turned on the knob to enable it to do reverse lookups. only the mild version, a reverse is made on the ptr rr for the ip address sending the email. if it fails the spam filter issues a 421 and closes the connection. unfortunately, we have 6 sites thus far that are legitimately trying to communicate with us but don't have ptr's associated with the ip address sending emails. since it obviously isn't a requirement to have one is it generally accepted to do so? any sense for how many end networks do and don't?
thanks in advance.
