RE: Bit OT but it's about SPAM

Well, in our case, if they are false positives being blocked at the MTA level, then:

1. the host is listed in a very reliable blacklist which is easy to delist from (CBL) and would thus be blocked by a great number of other's mail servers. I'd trawled our logs and already made exceptions to cover the one clueless sender whose emails would have been "erroneously" blocked by the CBL.
2. they are using broken SMTP agents and not following RFCs (sendmail's greetpause). I check the sendmail logs to catch broken legit mail servers and whitelist them.
3. they don't retry after being greylisted (and to get greylisted in the first place they have to be on a pretty reliable RBL).

And a random delve into the depths of my sendmail logs confirms that all is well.

We have a bunch of rules in our sendmail access file to ensure that false rejects do not happen.

Cheers,

Phil

--
Phil Randal
Network Engineer
Herefordshire Council
Hereford, UK  

> -----Original Message-----
> From: Bart Schaefer [mailto:barton.schaefer@gmail.com] 
> Sent: 18 October 2007 15:14
> To: users@spamassassin.apache.org
> Subject: Re: Bit OT but it's about SPAM
> 
> On 10/17/07, Randal, Phil <prandal@herefordshire.gov.uk> wrote:
> > Hyperbole?
> >
> > Well, let's take a look at the figures on my mail relay boxes
> 
> Not to single out Phil, but so far everyone is quoting (among other
> things) the percentage of mail that they reject out of hand.  You're
> all 100% confident that none of those were false positives?
> 
> My point was that "rejected/filtered by anti-spam techniques" and "is
> spam" are not synonymous, but nearly everyone who publishes spam
> figures behaves as if they were, and most of them have a vested
> interest in making the number sound as big and scary as possible.
>