It has taken me several months to come up with the
combination of DNSBLs I posted earlier. The process
was something like this: add a dnsbl, then very
closely monitor (manually) the bulk folder for at
least a week. On the first false positive, the dnsbl
responsible would be removed, then on to testing
another.

The domain has roughly 80 email accounts - here's a
typical weekday's stats (in fact, Friday's):

9360 Total incoming emails

6780 invalid addresses (mostly harvesting)
1739 caught by DNSBLs
134 containing blacklisted URLs
25 trashed thru statistical filtering (2 false +'s)
11 phrase filtered
10 virus

661 delivered

I'm not sure where you're coming up with the 2%
figure, but if that were the case, I would have had 35
false positives on Friday. I personally reviewed ALL
of the junk mail (ugh), and found 0 due to dnsbl's. In
fact, the only problem I've had with them in the past
couple of months was due to a client trying to email
us from their "spiffy new in-house email system" which
was configured as an open relay.


--- "R. Scott Perry" <[EMAIL PROTECTED]> wrote:
> FYI, at least 2 of those tests would each catch
> about 1% of our legitimate 
> mail (all those tests combined would probably result
> in about 2% false 
> positive ratio here).  So while it may be very
> effective for you, others 
> should be very careful before following the advice
> (most people seem to aim 
> for a false positive ratio of about .1% or better).
> 
>                                                    
> -Scott
> ---
> Declude JunkMail: The advanced anti-spam solution
> for IMail mailservers.
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> 
> ---
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