[SURBL-Discuss] OT: RBL needed!

[Jeff Chan]

On Friday, May 28, 2004, 6:55:23 AM, Doc Schneider wrote:
> I got a whole bunch of open relays doing rumpelstiltskin(sic) attacks on
> both my main mailserver and my seconary MX server... hitting the 
> secondary and making it throttle the main one.

> Anyway is there a way to use some of these RBLs to basically deny these 
> open relays to be able to even attempt these attacks?

> I'm running  Sendmail 8.12.11 on Linux... both these boxen run RH 6.2 
> and are really locked down against other attacks.

Many people use and recommend list.dsbl.org and xbl.spamhaus.org
(or sbl-xbl.spamhaus.org) to block open relays at the MTA level.
(sbl-xbl is a combined list of sbl and xbl.  ;-)

We find them quite effective.

Here are my mailserver.mc (m4) confs:

FEATURE(dnsbl,`sbl.spamhaus.org',`"Address "$&{client_addr}" blocked. See http://www.spamhaus.org/sbl/"')dnl
FEATURE(dnsbl,`xbl.spamhaus.org',`"Address "$&{client_addr}" blocked. See http://www.spamhaus.org/xbl/"')dnl
FEATURE(dnsbl,`list.dsbl.org',`"Open relay "$&{client_addr}" blocked. See http://dsbl.org/sender"')dnl

Jeff C.