Im not sure of your logic about disabling the "invalid in-addr.arpa" filtering from your sendmail. I wouldn't do it for just one of my customers and expose the rest of my customers to spammers that intentionally try to hide themselves by faking a return address and/or masking their relay server with a bogus name. I would tell that one customer to have their constituent with no reverse DNS to get there setup corrected because: a. It is a proper and complete DNS config to have reverse mapping to your ip b. It makes all data originating from it accountable (not just spam but smurf attacks, DOS attacks, port scans/Satans etc.) to the organization/person responsible for the forward and reverse zone (if they match) c. It gives other ISP's and businesses the choice to filter or not filter. If one of us makes policy to make exceptions for a customer, then they tell other customers who tell other customers who tell other potential customers that an ISP should not filter e-mail on this premise. Let the 1 in 5 people in the Internet who are either lamers who don't know how to do reverse DNS properly or too lazy to do it keep their problems as their problems and not ours. Already there are a ton of TCP wrapper applications, FTP sites, telnet sites, Netscape U.S. Encryption pages for Navigator, etc that will not allow access with improper or non-existant reverse DNS entries. Would you consider not doing gethostbynames on your entire web server because one of your web clients wanted their mis-configured customers elsewhere in the internet to have that much faster access on web pages which would also give the rest of your customers stat pages full of IP's only ?? I wouldn't...... None of my customers have complained about us filtering the misconfigured in-addr.arpa people. 80% of my customers are business who exchange a lot of mail with other businesses on the net, maybe they don't care ? I dunno. As for responsible service providers disconnecting abusers, we have disconnected around 10 of them so far. I guess wer'e luck we haven't ran into a Spamford Wallace yet huh ? Just my opinion, thanks for tolerating it. Paul Peterson, WinterLAN Inc.

-----Original Message----- From: Jon Lewis [SMTP:jlewis@inorganic5.fdt.net] Sent: Wednesday, October 29, 1997 9:25 PM To: Cal_Thixton@TPA.Net Cc: Phil Lawlor; nanog@merit.edu Subject: Re: Spam Control Considered Harmful

On Wed, 29 Oct 1997, Cal Thixton - President - ThoughtPort Authority of Chicago wrote:

...

I personally see no practical technical means of eliminating the practise of spamming and rather than spending time trying to dream up fancier and smarter sendmail's, we should seek to simply expand the current mail fraud laws to cover electronic mail. Then we can simply sic the FBI on these people armed with terabytes of logs and spam emails

And what will the FBI do when spammers leave the US and do their deed from other countries? Spammers won't be stopped by legislation or technology...the average internet user can't handle the amount of technology necessary to keep spam out of their mail. The average sysadmin isn't much better off. I had to disable my latest anti-spam sendmail rule today (denying incoming mail from sites with no or incorrect in-addr.arpa DNS) because a client is trying to do business with a site that has existed for a year an a half and never setup in-addr.arpa DNS.

Spam can only be stopped by responsible providers not allowing their clients to abuse the net. Phil's attitude of "We provide internet connectivity. If you don't like spam, _you_ do something about it." has nearly destroyed AGIS. Who's going to be next?

BTW...Cal...obtain a linefeed.

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