Re: Reduce the amount of spam for @debian.org (Was: Greylisting for @debian.org email, please)
gmail.com used to do that to lists.debian.org. We deliver ~300,000
emails to gmail a day. It resulted in some deliveries timing out before
they were even attempted; I'll let you imagine the rest.
Cheers,
Pasc
On Fri, 2005-06-17 at 08:35 +0200, Petter Reinholdtsen wrote:
> [Santiago Vila]
> > For example, we could use greylisting. Or we could reject messages that
> > are known to come directly from trojanized windows machines acting as
> > open proxies. Or even better, we could do both things.
>
> Or a completely different option. Here at the university the
> postmasters implemented a system to delay delivery based on blacklist
> entries. The delaying is done during the first connect, and does not
> require the MTA in the other end to reconnect, like greylisting. The
> idea is simple:
>
> - Keep/use a list of good and not soo good blacklists for MTA hosts.
>
> - If the other side is listed in one of this blacklists, act as a
> _very_ slow SMTP server. The initial hello reply is delayed 1-2
> minutes in this case, and if the client try to send anything in
> this period, the connection is dropped. The SMTP protocol specifies
> that the client should not send anything before receiving the intro
> line from the other end, so this is safe to do.
>
> - This reduced the amount of spam with more than 90 percent, I've
> been told. The current spam software do not seem to have time to
> wait for a reply, or give up the delivery after a few seconds
> without any reply. In either case, all standard-compliant MTAs are
> able to get their mails through, even if they are listed in a
> blacklist.
>
> - MTAs not listed in a blacklist is passed throught without any
> delays.
>
> Could this be an idea for Debian as well?
>
>
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