In order to block spam but not block individual messages we began tracking total number and average score of messages sent in the last ten minutes, one hour, one day and last 30 days. Since dial-up subs can have a different IP address each time they connect we have to start by tracking back to the "real" userid from the sending IP address.
A sub could send a few emails scoring anything (could be a personal porn-o-gram to someone :) but the higher the number of messages the lower the average score can be to trigger blocking. Rate of transmission also weights the decision - sending 100 in a few minutes is treated like sending 1,000 over a longer time.
We are still playing with the rules, but so far so good. We no longer get reported to spamcop or other block lists, and the only subscribers who have had an issue are people who were really spammers - they all claimed that they were sending out newsletters until shown the spam reports.
John Scully www.isupportisp.com
----- Original Message ----- From: "David F. Skoll" <[EMAIL PROTECTED]>
To: "MimeDefang" <[email protected]>
Sent: Thursday, February 17, 2005 12:48 PM
Subject: Re: [Mimedefang] Scary... Filtering on the outbound.
On Wed, 16 Feb 2005, Ben Kamen wrote:
[about outbound filtering]
This is going to become a lot more common for a couple of reasons:
1) As ISPs block outbound port 25 connections, spam zombies are going to use the ISPs relay to send outbound spam. This will force ISPs to filter outgoing mail, or risk getting blocked as spam sources.
2) All kinds of regulations in the US like HIPAA and financial regulations will force businesses to at least pretend to control outflowing information. Unfortunately, doing this effectively means prohibiting tools like PGP for encrypted e-mail. :-(
Regards,
David. _______________________________________________ Visit http://www.mimedefang.org and http://www.canit.ca MIMEDefang mailing list [email protected] http://lists.roaringpenguin.com/mailman/listinfo/mimedefang
This message scanned for viruses by Lifegiver.net For more information on our filtered email and dial up internet service please visit http://www.lifegiver.net
_______________________________________________ Visit http://www.mimedefang.org and http://www.canit.ca MIMEDefang mailing list [email protected] http://lists.roaringpenguin.com/mailman/listinfo/mimedefang
