[Mailman-Users] Limited posting

[J C Lawrence]

On Tue, 2 Oct 2001 15:06:34 -0400 
Jon Carnes <jonc at haht.com> wrote:

> I hate to say this, as I totally despise spam but...  to get a
> truly accurate count of folks who really open or at least preview
> the message, send the message as html and include a link to a tiny
> gif on one of your web servers.  Place the gif somewhere
> unobtrusive in the message, like at the very end.  

This is called a "web bug" and is a standard technique of both
SPAMmers and advertising companies ala DoubleClick, and is one of
the primary reasons I refuse to let HTML on any of my lists (as I
promise my members privacy).

> The text of the message will always show up and as folks read the
> message, their machines will automatically download the gif.
> Actually, just previewing it will cause the gif to be downloaded.

Its also particularly easily defeated.  Just configure your MUA to
use a non-existent proxy for all HTML fetches.  In my case I point
it to localhost on a port which has nothing listening on it.  The
result is that the GET request is made to a non-existent proxy,
which never replies, and so the image is not retrieved.  Easy, low
impact, workable.  This way I get to read the mail but don't have to
worry about the unannounced and unwelcome privacy invasions of web
bugs.

-- 
J C Lawrence
---------(*)                Satan, oscillate my metallic sonatas.
claw at kanga.nu               He lived as a devil, eh?
http://www.kanga.nu/~claw/  Evil is a name of a foeman, as I live.