Re: Greylisting for @debian.org email, please
On Fri, 2005-06-17 at 10:45 +0900, Miles Bader wrote:
> Wouter Verhelst <email@example.com> writes:
> > What's painful about it?
> > It stops a lot of viruses and spam, with no false positives. What's the
> > problem?
> "No false positives" seems a bit optimistic.
> One problem I've encountered in the past is big mail providers (like
> yahoo) who will send retries from _different_ servers, which sometimes
> don't even have a DNS entry (maybge it's just DNS propagation delay, I
> don't know).
> How do greylisting services determine that a message is being resent
> (and so should be accepted this time)? If it's by hostname or host
> address, this would sometimes fail with systems like the above.
I've had pretty good luck by matching by /24. The mail servers will
usually be within that range. This has worked for the mail I host in
terms of receiving from yahoo, ebay, hotmail, etc, etc
Realistically, it's not a solution to spam, but it does at least cut
down on what you get a fair bit.