On Fri, 2004-11-26 at 03:25 -0800, william(at)elan.net wrote:
On Fri, 26 Nov 2004, David Woodhouse wrote:
It would certainly be interesting to see a study of how CPU load on mail
servers would be affected by DK; especially one which recognises the
fact that you don't actually have to run other CPU-intensive checks like
SpamAssassin and virus checking on mails which were already rejected due
to the crypto check.
Thanks for posting your notes. I'm not sure what conclusions to draw
from them -- I can't really see whether these data confirm or refute my
assumptions. Which are that the added CPU load will be partly offset by
the reduced CPU load needed for other things like spam and virus
checking on the mails which the crypto scheme allows you to reject, and
that the resultant CPU load increase is easily accommodated by the fact
that these machines weren't highly CPU-bound in the first place.
I was looking ideally for something like a comparison of CPU
utilisation. Watch the machine for a day with a real workload, while it
does spam and virus checking. Then take a copy of everything it received
and DK-sign it as appropriate (sign all valid mail, attempt to sign a
tiny proportion of the spam with an incorrect signature). Presumably
leave most of the spam unsigned. Then play it back to an identically
configured machine and watch the CPU load on that as it does all the DK
stuff too.
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And getting back to SPF, I took some notes on the statistics that
were presented at well.
1. Godaddy statistics (?)
7% of emails go Godaddy have SPF records
18% of emails are rejected based on SPF
14% of SPF emails are from known spammers
2. Earthlink numbers
90% of emails that passes SPF is spam
90% of emails that fails SPF is spam
So 10% of the mail that fails SPF is valid? That's a lot. Or does 'spam'
in this context not include certain classes of unwanted stuff, like
viruses?
40% of emails that does not publish is spam
What I'd really like to see in these statistics is the number of spams
mails which are rejected by SPF which _wouldn't_ have been rejected by
other means, vs. the number of false rejections, which is possible the
10% quoted above although as I said, that seems higher than I expected.
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On separate note sheet I have the following from the 1st day:
I see the jesters are out in force again :)
No need to scan the paper of which you speak -- I think it's on their
web site.
--
dwmw2