On 2008-02-26, OpenBSD - Wire Consulting <[EMAIL PROTECTED]> wrote: > Freemail hosts like yahoo, hotmail and google have a huge number of > servers which are used to send the email coming from this domains. > The problem I found some time ago, was that the retries didn't come > always from the same server. This simply blows up the greylist principle.
They often come from within the same /24 though. Most (!spamd) greylisting implementations mask off the last byte of the address to avoid this problem and greylisting.org by policy no longer adds common-queue senders to their lists if they're all from within a /24. imo this problem is less likely to be seen on a very large mail system, since enough mail is going through that most of the common-queue pool is likely to stay whitelisted by spamlogd, but I think it can sometimes be a problem on smaller installations.
