nanog mailing list archives

RE: How do you stop outgoing spam?


From: "Al Rowland" <alan_r1 () corp earthlink net>
Date: Mon, 9 Sep 2002 10:18:37 -0700


Kinda breaks broadband streaming audio/video in a Java/other web applet
though...among other things.

Best regards,
_________________________
Alan Rowland


-----Original Message-----
From: owner-nanog () merit edu [mailto:owner-nanog () merit edu] On Behalf Of
Iljitsch van Beijnum
Sent: Monday, September 09, 2002 3:50 AM
To: Hank Nussbacher
Cc: nanog () merit edu
Subject: Re: How do you stop outgoing spam?



On Mon, 9 Sep 2002, Hank Nussbacher wrote:

The spamming is usually done (but not only) from an Internet cafe 
where the spammer inserts a "spammer CD" and blasts away at open mail 
relays.  When SMTP is blocked for that IP, they switch to HTTP and 
send the spam via MSN, Yahoo, Hotmail, Kukamail, Outblaze, Safe-mail, 
etc. to name just a few.  Blocking port 80 is harder since it requires

maintaining an ever larger list of free public web based mail systems 
or just block port 80 entirely.

You could traffic shape or rate limit the traffic towards port 80 to a
few kbps for each IP address that might be used for spamming. If you
allow small bursts (10 - 50k) this should be just fine for regular web
access, since for that outgoing traffic is minimal: just the HTTP
requests and ACKs. However, it will slow down spamming to at most a
couple dozen spams per minute after the first few that fill up the
configured burst size. I imagine this will make the spammers move on to
greener pastures.



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