Re: [exim] SPAM Filtering - Losing the war!

Sometime around Tue, 24 Oct 2006 18:39:34 +0100, it may be that Chris
Lightfoot wrote:
> The point here is *false* positives, and whether the

Or what I term 'unintented blocks' ... a term I've been using since
before spam was a large problem. (I recall I used it in reference to
accidentally blocking coloured book mail forwarded from a VAX onto a
Unix box because the address format was 'invalid').

> decision about whether something should be treated as spam
> should be up to the addressee, or up to some MTA
> administrator exercising a technical prejudice.

Different organisations have different levels at which unintended
blocks are acceptable. An ISP may prefer a level of zero (where the
user is paying for a service); another ISP who claims to block most
spam may have a level somewhat higher.

Where the email address is provided primarily for work related purposes
and email is read during work time, the organisation may decide that a
higher level of unintended blocks is acceptable. Letting users deal
with spam has a high cost to an organisation (a back of the envelope
calculation several years ago indicated I was saving £500,000 a year
with anti-spam measures ... and I was probably underestimating by quite
a way).

Sometimes I get it right, and sometimes I get it wrong. But as I've
been a Postmaster for 13 years and haven't been fired yet, I'm
obviously not totally off the wall.

--
Mike Meredith, Senior Informatics Officer
University of Portsmouth: Hostmaster, Postmaster and Security
If you play the Windows CD backwards you hear a satanic message.
But it gets worse... If you play it forwards it installs Windows.