Daniel Tiefnig (exim@???) said, in message
<4214741B.1040100@???>:
>
> Christian Schmidt wrote:
> >> RFC2821 states "while mail that cannot be transmitted immediately
> >> MUST be queued and periodically retried by the sender."
>
> Yes, but the thought, that we have to queue every single ******* message
> in the first place just because someone's greylisting, makes me kind of
> sick.
Greylisting doesn't force people to queue every single *******
message. Last April I gave a talk about our greylisting system
(
http://users.aber.ac.uk/auj/spam/greytalk.ppt), so had reason
to look quite closely at deferral stats:
Week 21st - 28th March 2004
Total sender/recipient pairs tried: 519,221
Total delivered: 204,096
Total delivered without delay: 165,702 (81%)
Total delivered within 2 hours: 93%
Uncompleted: 315,125 (61%)
Complaints received about undelivered mail: 0
Assumed spam: 61% of all mail attempted.
Sure, we see queued messages here as a result of greylisting, but they don't
exactly take a vast amount of resources. If you've got as many naiive users
as I have, you're probably queueing many many more "remove me from your
mailing list" replies to addresses which are deferring due to their mailbox
being over quota!
By using greylisting here, we're saving vastly more processor, disk and
staff time than is used up by our having to queue mail to sites who
greylist our outbound mail, and I'm more than happy to take that extra
load.
Greylisting is currently a very good tool. Sometime soon it won't be. But,
in the past 16 months I've been able to forget about spam and get on with
the other 90% of my job :-)
Cheers,
Alun.
--
Alun Jones auj@???
Systems Support, (01970) 62 2494
Information Services,
University of Wales, Aberystwyth
