[ On Tuesday, June 7, 2005 at 23:15:10 (+0100), Mark Smith wrote: ]
> Subject: RE: [exim] Reducing load vs seeing all the spam
>
> > > > I'm assuming you're mistaken -- there must be a way to whitelist
> > > > against RBL checks no matter where in the transaction the check is done.
> > >
> > > If you've come up with some way of checking the envelope sender at
> > > connect time, I'd be very interested to hear it.
> >
> > RBLs aren't about envelope sender addresses -- they're about
> > the client IP address.
> >
> > Unless you're thinking of basing your whitelist on the sender
> > address, which would be a really stupid idea in my estimation
> > since that's just as easily forged.
>
> One example is a third-party mailing list provider that seems to send out
> nothing but spam, except for one particular mailing list that we need to
> accept. In this case, the only way to distinguish between the spam and the
> mail we want is not even the sender address, but the From: header.
What does that have to do with RBLs and the local postmaster mailbox?
Is the list sender listed on some RBL you use?
Does the list sender use a list-specific sender address?
If the answer to both those questions is "yes", then whitelist the list
sender so the RBL doesn't block them, then set up your MAIL FROM: access
controls to block everything from their domain but the one list you
"need" to accept (and maybe their postmaster(s)).
However if/when they start sending you spam by biasing it with the same
sender address of the list you "need" to accept from them, well you'll
either have to accept that spam, or you'll have to find some other way
for your users to continue to be members of that list's community.
--
Greg A. Woods
H:+1 416 218-0098 W:+1 416 489-5852 x122 VE3TCP RoboHack <woods@???>
Planix, Inc. <woods@???> Secrets of the Weird <woods@???>
