Darth Lists wrote: > Unfortunately, this little MS-behaviour is very likely to be the "last > straw" that gets our greylisting turned off here. > Despite my logs that prove that greylisting has removed over 95% of > incoming spam before spamassassin has to deal with it, the fact that > some legitimate mail is lost or overly delayed has been deemed > unacceptable to the corporate masters.
Well, I think greylisting is still useful. It is just that if you want to avoid losing mail or having it too much delayed, you should adjust the settings for greylisting from 1h/4h to 9min/36h. Many mailers have their queue runners at 15mins. Putting 36hours allows you to get mails from servers with common pools or weird retry delays. These values were just deduced from trial and error. Also greylisting should happen at RCPT TO, and probably not at DATA as there are some widely used MTAs that are buggy and choke when a 4xx error is sent in the DATA phase.
