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Re: [Asrg] Spam detection system proposal

2003-03-05 09:12:03
David F. Skoll wrote:
On Wed, 5 Mar 2003, Vernon Schryver wrote:


I disagree, because many spammers work hard to remove bad addresses
from their target lists.  Other spammers don't, but still others work
hard to honor "unsubscribes" or "removes."

In order to remove bad addresses (as Justin Mason pointed out), or honor
unsubscribes, spammers would need to supply either a valid return address
or a Web page somewhere that's trackable.

Sorry, wrong. All bad address removal requires is spamware that understands SMTP error codes. No reverse channel of any kind required.

You can't clean your list unless you can receive bounces,

Wrong as per above.

Most spammers don't care about rejects.  They really don't.

Really.  Truly.

2 years ago we decommissioned (de-MX'd out of DNS) several domains we no longer used, but were getting 50,000 spams/day. After 18 months of solid failures, I reenabled the domains to see what's happening.

500,000-700,000 spams/day. Plus a big chunk of bounces from ISPs from spam forged in these old domains.

Or, see http://striker.ottawa.on.ca for a situation that's even worse. A domain is so badly hit with spamming attempts for addresses that _never_ existed, that he can no longer afford the SYN packets to reject inbounds at the TCP layer.

Hell, even some legitimate emailers don't notice rejects and never clean bogus addresses.

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