Re: faked from addresses getting through to my lists

On Tue, Jun 15, 2004 at 11:55:24AM -0500, Terry Todd wrote:
> OK forget I ever suggested using smartlist as a spam filter.  I've
> tried many many other spam filtering solutions.  None of them work
> 100%. So I wrote my own that is essentially the same thing as what
> I suggested here.  It is a whitelist of only those I accept email
> from. It works. 
> 
> The original problem is spam got through to a smartlist mailing list
> by header information being faked.  How can that be prevented?  
> What do others using smartlist do to prevent this from happening?

My spam filter checks for forgeries of my address in the From:
field by screening against the small set of comment fields I use.
I can do this for myself, but there's no way I could consider this
sort of screen for anyone else, for obvious reasons.

It sounds as though this approach might work for Terry, and if he's
already written a spam filter he's comfortable with, dropping in 
another recipe should be easy.

FWIW, here's mine:

#
# Fake real name:
#
:0
* ^()\/(From:[ 	]*".*[A-Za-z]+.*"[ 	]*<jimo@eskimo\.com>)
{
	FNAME=$MATCH
	:0
	* ^From:[ 	]*\/".*[A-Za-z]+.*"
	* ! MATCH ?? <my-list-of-valid-comment-fields>
	{
		XSPAM = "${XSPAM}${XSPAM:+, }FAKENAME"
		:0 fwh
		* $!${addheaders:+!}
		| formail -A "X-Diagnostic: fake real name: $FNAME"
	}
}

Good luck,

Jim