Re: [tlug] state of the art spam filtering

[Attila Kinali <attila@example.com>]

Salut,

On Tue, 16 Mar 2010 13:58:41 +0100
Francois Cartegnie <fcartegnie@example.com> wrote:

> Prior checking content:
> * Reject senders without reverse

This will kill all people who have a clueless ISP.

> * Reject senders listed in RBLs (spamhaus works well)

After the MPlayer/FFmpeg server has been listed a few times
in RBLs (probably for backscatter or users using the spam button
for unsubscribing), my regard for RBLs has pretty much diminished.

> * Reject senders with reverse DNS containing their IP (Catches 90% !)
> * Reject senders with reverse subdomain containing blacklisted works (ex: 
> *dyn*.foo.com, *dsl*.foo.com, *ppp*.foo.com, ...)

This prevents any sender who is using a machine at home for outgoing
stuff to send mail.
 
> Works, but I don't use it because of lots of false positive (because most 
> sites sends mail through web scripting):
> * Reject senders which are not MX

Err.. of course! Nobody says that you have to use the MX for your
domain for sending. Actually, most often it is not the case!

			Attila Kinali

-- 
If you want to walk fast, walk alone.
If you want to walk far, walk together.
		-- African proverb