[Mimedefang] Re: Filtering idea for stock pump&dumps

[G.W. Haywood]

Hi there,

On Mon, 2 Jul 2007, Kevin A. McGrail wrote:

> > > This PDF spam is tough.
> >
> > Greylisting stops quite a bit of it.
>
> FYI, based on what we have confirmed over the past 2 weeks, greylisting is
> causing widespread FPs with Microsoft Exchange 2003 SP2.  In short,
> Microsoft is interpreting 4XX errors as 5XX errors and generating NDRs.

If broken mailers receive responses that they (and their users) don't
expect, then perhaps that will be an incentive to fix them, or to stop
using them.  I don't much care either way.

FWIW I've never seen one of these messages.  I haven't done anything
specifically to prevent them getting through.  Those of you who can
remember my somewhat uncompromising approach to mail filtering might
not be surprised by that; those that don't might want to take a look
at the List archives - I'm not a prolific poster - or maybe at

http://www.ii.com/internet/robots/procmail/qs/#spam.

Yes, I still get a few false positives.  I'd much rather deal with
those than with tens of thousands of false negatives, just one of
which (together with a little human frailty) cost a friend of mine
fifteen hundred dollars.

--

73,
Ged.