paulm@??? said:
> How do these rate-limit?
Exim doesn't really have rate limiting. The smtp_accept_max_per_host
was there to stop a single host running you out of resources.
Coincidently it works rather well to slow down a determined spammer
whilst other rate limiting goes into action.
I had some perl which watched the exim main log (use File::Tail), and
recorded numbers of incoming messages per ip address. When a trigger
value was reached it added the ip address to a block database and tried
to explicitly freeze all message ids seen from that ip recently. The
system filter checks if a message came from that ip and froze them.
Obviously the blocks were also expired off.
This is pretty simple to write and integrate into exim and worked well.
Doing full rate limiting within exim needs some inter-exim comms that
aren't available in the current model. BTW a perl filter within exim
could probably do the same as the stuff described above but probably
with a slightly higher loading but lower latency.
Nigel.
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[ Nigel Metheringham Nigel.Metheringham@??? ]
[ Phone: +44 1423 850000 Fax +44 1423 858866 ]
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