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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical 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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