Date: Thu, 10 Mar 2005 05:17:09 -0500 From: Charles Swiger <cswiger@mac.com> To: Ted Mittelstaedt <tedm@toybox.placo.com> Cc: "freebsd-questions@freebsd.org Questions list" <freebsd-questions@freebsd.org> Subject: Re: how to deal with spam for good? Message-ID: <c26183b94fad2e2da6b0e029a1e388b1@mac.com> In-Reply-To: <LOBBIFDAGNMAMLGJJCKNIELBFAAA.tedm@toybox.placo.com> References: <LOBBIFDAGNMAMLGJJCKNIELBFAAA.tedm@toybox.placo.com>
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On Mar 10, 2005, at 4:49 AM, Ted Mittelstaedt wrote: > This is bullshit, milter-greylist is in the ports. Greylisting > does not require postfix. Just because YOU are too lazy to > understand sendmail doesen't mean everyone else is. I've paid my dues to sendmail: http://groups-beta.google.com/groups? &as_ugroup=comp.mail.sendmail&as_uauthors=Chuck+Swiger ...shows about 900 postings from me. As of sendmail-8.11, and even early 8.12's perhaps, greylisting via sendmail wasn't possible because the MILTER API didn't support it. If the situation has been improved and you can greylist with sendmail now, that's fine. What isn't fine is your attitude: FOAD. > Keep in mind that Greylisting isn't going to be very effective > for long if a lot of people adopt it. Your opinion differs. > If our customer's coorespondent cannot get mails from us and from > hotmail, how long do you think he's going to put up with his ISP > running a greylist? If a customer isn't happy with you, they'll take their business elsewhere. Lord knows I wouldn't blame them, either. > Long before this happened of course the spammers would mod their > software to simply start retrying more. If you think about it, if > they are sending a million mails a minute, and the greylist delay is > 5 minutes, they merely need to construct a server that stores 5 > million mails for a set period and then retries. The server never has > to store more than 5 million mails at a time. Let them retry more. There is more than one way to deal with UCE, and shifting the burden to the spammers, making them consume lots of time for minimal resources is amoung those ways. > It's just one more anti-spam filter that is utterly dependent on > nobody else on the Internet doing it. Typical bright idea from some > tech somewhere that understands just enough of the SMTP standards to > cause a lot of trouble for people. Someone whose SMTP engine is unwilling to retry delivering email after the first response is refused with a 4xx code is the one failing to understand RFC-822/2822. Real mailers retry at a recommended 1 hour interval for a recommended maximum queue length of 5 days, per RFC. Once you've whitelisted your clients and covered 95+% of incoming mail, up your greylisting time from 5 to say, 59 minutes, works wonders. > The only long term solution that is going to work is modding the > DNS records to designate an official SMTP server for each domain, such > a plan has been in the works for a while among the standard bodies > that know what they are doing. SPF is another way of dealing with UCE. It's not hard to find people who have implemented SPF in their DNS, either. I haven't seen it do much good as yet... -- -Chuck
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