AOL rejecting mail from IP's w/o reverse DNS ?

Suresh Ramasubramanian suresh at outblaze.com
Thu Dec 4 22:41:55 UTC 2003


Petri Helenius  writes on 12/4/2003 5:36 PM:

>> Yup. The model can be extended to "if no rDNS, and if spamtrap hits or 
>> other spammish behavior noted from more than X IPs per /24, then block 
>> the /24".
>>
> And why would blocking the /24 be appropriate instead of matching the 
> registry?

I would refer you to the huge number of netblocks out there that stay at 
/16 or larger size, with the upstream not SWIP'ing or otherwise 
delegating netblocks in APNIC (or wherever, such as an rwhois server) as 
they provision IPs.

	srs
-- 
srs (postmaster|suresh)@outblaze.com // gpg : EDEDEFB9
manager, outblaze.com security and antispam operations



More information about the NANOG mailing list