Date: Sat, 30 May 2009 10:20:06 +0200 From: Erik Norgaard <norgaard@locolomo.org> To: Mel Flynn <mel.flynn+fbsd.questions@mailing.thruhere.net> Cc: freebsd-questions@freebsd.org Subject: Re: Greylisting and new posters Message-ID: <4A20EC36.6080003@locolomo.org> In-Reply-To: <200905292311.58235.mel.flynn%2Bfbsd.questions@mailing.thruhere.net> References: <200905292311.58235.mel.flynn%2Bfbsd.questions@mailing.thruhere.net>
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Mel Flynn wrote: > Is it possible to: > a) Put a big-red-blink-popup-attentiongrabbing monster text into the > subscription page about first posts being delayed with a link to greylisting? > b) Hash the bodies of greylisted messages and reject / discard if the same > body with a different msg id is being received? > > I'd be happy to contribute to b) if it is thought that the incoming mailer can > handle the hashing and storage of this information. Hi, ok sorry about that mail yesterday :) I've been off the list for some time. It would be great if the confirmation mail and the subscription page would include the message: "After confirming/activating your subscription your first mail may be delayed X minutes due to grey listing" Also, it would be great to have a descriptive error message, rather than this: 450 4.7.1 <questions@freebsd.org>: Recipient address rejected: Service is unavailable (in reply to RCPT TO command)) This text message indicates an error in the recipients end, while the 450 status indicates it's temporary. IIRC the postgrey port will provide a message along the lines "sender postgreyed X seconds, see website for more information." Your option b) won't work: you propose to reply with a 2XX (OK) or 5XX (rejected, don't try again) if subscriber sends the message again. Problem is that the server after receiving the 450 error will retry after some time and this may be before the sender is white listed. So if you implement the solution you propose you risk that the original message is either discarded or rejected. So, you need to come up with an idea of how to distinguish between the server resending the same message and the subscriber resending the same message. If anything, I believe it's most likely that the subscriber will not send the exact same message, missing some blanks or double signature line etc... Now, you could take an active approach, when a subscriber's first message is grey listed, send an automatic reply that the message is grey listed for X seconds. But, then you have the problem that these auto replies will also be sent to innocent people who are being impersonated by some spammer, or to non-existing mail addresses which will generate loads of error messages. Question: Did grey listing actually reduce the amount of spam on the list? I eventually dumped it as it caused more problems than it solved. BR, Erik -- Erik Nørgaard Ph: +34.666334818/+34.915211157 http://www.locolomo.org
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