No spam???

[Warren Block]

On Tue, 15 Jan 2008, cpghost wrote:
> On Tue, Jan 15, 2008 at 08:48:32AM -0500, John Almberg wrote:
>>
>> So raises the same point that Oliver makes: how trustworthy are these
>> blacklists?
>
> YMMV, of course!
>
> I'm using spamhaus.org's blacklists for quite some time (many years)
> to block spam in postfix and they've been VERY trustworthy so far.
>
> But I can't say the same for the others, which seem occasionally a
> little bit too eager/aggressive and accumulate way too many false
> positives.

"Trustworthy" is entirely subjective in this case.  I've seen people 
complain about high false positives with a DNSBL that has been extremely 
trustworthy for me, and then turn around and recommend one that had a 
very high false positive rate.

In general, people should check a DNSBL's blocking criteria and 
reputation before using it.  They should also realize that's it's not an 
exact science, and be willing to manually whitelist and otherwise adjust 
things from time to time.

-Warren Block * Rapid City, South Dakota USA