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

Suresh Ramasubramanian suresh at
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 (postmaster|suresh) // gpg : EDEDEFB9
manager, security and antispam operations

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