Re: [exim] binning mails on delivery based on headers

Top Pagina
Delete this message
Reply to this message
Auteur: John Oxley
Datum:  
Aan: exim-users
Onderwerp: Re: [exim] binning mails on delivery based on headers
Sorry I previously replied to Alan instead of the list.

On Fri, Sep 30, 2005 at 10:41:56AM +0100, Alan J. Flavell wrote:
> On Fri, 30 Sep 2005, John Oxley wrote:
>
> > Okay I have mails coming through a spam/virus filter to a separate
> > box running exim 4.52 and courier-IMAP/POP on FreeBSD 5.4.
>
> Then, to be candid, I'd want to redesign the system. exim is an MTA:
> it's supposed to provide a reliable mail service, which IMHO means
> either positively accepting, or positively rejecting, mail items.
> Silently dropping items into a black hole (automatically, without
> postmaster/admin intervention) isn't an option that I'd care to
> consider for the MTA, due to considerations of false positives: (if
> individual users want to construct their own mail filters to do that,
> on their own authority, then that's different).


Granted. Seeing as you have said this, I will drop the refusing
ability, and just focus on the tagging side of things. What I was
thinking of doing is making the user realise that they are blackholing
this mail, but now I see why I shouldn't.

> Of course the (unstated) assumption of your posting is correct, that
> once an item has been accepted it's dangerous to automatically bounce
> it, due to faked envelope sender addressses; so, once it's accepted,
> if it's considered abusive then the only options would seem to be
> silently discarding it (as you've proposed) or passing it for
> postmaster/admin inspection. Since neither of those seem IMHO
> particularly attractive, my "take" is that one should avoid designing
> a system such that it provokes that situation. And that, to me, means
> designing the system such that a positive acceptance or a positive
> rejection is feasible at SMTP time.


What you have said is very logical and you have convinced me to go the
more difficult (I think anyway) method of clustering. We have a Summit
48i switch from Extreme Networks which I am told can do clustering, so
I'll implement that. Has anyone any experience with clustering exim on
FreeBSD servers?

-John

-- 
John Oxley
Systems Administrator
Yo!Africa
E-Mail:  john at yoafrica.com
Tel:     +263 4 858404
echo '9k[l:l;s<s=0l>x]s"[1+l<dd*l=d*-l;+ds<rl=2**l:+ds=d*rd*+4<-d15>>] s>[q]s-[d77/3*2-s;47l"x-P1+d78>`]s`0[d23/.5-3*s:0l`xr10P1+d24>$]ds$x'|dc