Author: Kjetil Torgrim Homme Date: To: exim-users Subject: Re: [Exim] Opinions sought: Most effective spam reduction
techniques
On Tue, 2004-08-17 at 12:35 +0000, Peter Bowyer wrote: > I suggest (and use) the following set of measures in our virtual-domain
> system, in order of increasing cost:
>
> 1. HELO checking - disallow bare IPs, HELO with any of your domains[1],
> HELO not FQDN[1]
> [...]
> We've not found any FP issues at all with stages 1-6
really? we have 2-3 cases per week where we reject e-mail from systems
without FQDN HELO, or the name contains underscore, or their nameserver
isn't responding (sender verify). we also get the odd false positive
from sites which are open relays. changing our policy isn't being
considered, and indeed many of these sites have fixed the problem after
we told them about.
(I call these false positives since the recipient actively wants the
correspondence.)
oh, and don't use SPF. MARID looks to be shaping up nicely, though.
--
Kjetil T.
