Re: [exim] SMTP processing hangs during bayes sync

On 8/31/06 6:19 AM, "W B Hacker" <wbh@???> wrote:

> Greylisting, BTW, is likely to more than double your connection load, (retry
> may
> be idioticlly rapid for zombies) - spawning child processes that may not go
> all
> the way through to the DATA phase, but will certainly consume resources.

We run a monitor which, every 5 minutes, queries our greylisting database
for /24 subnets which have sent "too many" messages "recently" deferred by
greylisting. We (really, "I") look at those--manually, still; the
idiotically rapid retriers among them stand out for their high
blocked_attempts counts and are easy blacklisting decision--blacklisting
keeps them out of greylisting processing.

I don't see all that many. Much more often I'm late enough to the party
that I see non-retrying zombies (which I blacklist mostly for record-keeping
reasons). (Our blacklist database allows for either hosts or /24s--a
dynamic IP with an infected machine leads to blacklisting the /24, of
course.)

--John