rbls in sendmail

[Raymond Dijkxhoorn]

Hi!

> What does checking Received Headers really do for you? (its a good
> question!). Sendmail is checking the last place that the mail came from
> against various RBLs and blocking it on that basis.
>
> We have found that too much checking below that level can result in lots of
> false hits, since a lot of legitimate email comes from places centered
> around the IPs the RBLs block. So our use of the RBLs where they are
> actually has shown some benefit for us.
> If I wanted to block using RBLs further into the mail header I would likely
> go the Procmail route - though aside from blocking some IP ranges
> (currently, as 2nd level SPAM blocks), that has not seemed to make much of
> a difference here since they change so much.

I disagree, many open proxys send out via their ISP mailers, so called
multiple hopping spammers. I see a lot of SA hits on those. Especially
with lists like DSBL.

Bye,
Raymond