does the X-Bogosity line mess up spamicity calculations?

[David Relson]

On Wed, 4 Aug 2004 21:24:32 -0300
Trevor Smith wrote:

> For now I have not been using -u when I run bogofilter (while I
> manually observe if things are working). After I confirm that spam and
> ham are separated as they should be, I train bogofilter with new
> messages that have come in. But these messages already have an
> X-Bogosity line in them. Is this undesirable? Does it matter at all?
> Does it matter a bit, but not enough to really matter?

Good question!

Bogofilter checks for the "spam header line" (as it's officially known)
and ignores it.  This prevents a spammer from deceiving bogofilter.  As
this is configurable, you can change it and have, for example, an
"X-Haligonian-Spam-Score" line.

If this check wasn't present, the tokens from the line would end up
neutral (with score near 0.5) since every message would have them.