On Fri, 13 Nov 1998, Andromeda wrote:
> A closer look at the headers revealed that the other host had HELO'ed with
> slcdug.org, which resolved to 209.90.71.51, not 209.90.71.31 as the IP had
> been. So Exim rejected it.
>
> By Jove... Exim is NASTY :)
with the configuration you described, exim did not reject because the host
lied when it said helo, but rejected because the IP address the message
came from did not have a proper name entry in the Domain Name Service
(DNS) system.
That is exim tried to do a reverse lookup of the IP address, but no name
was listed for the IP address.
Recently, I would say that at least half the spam I get is via hosts that
don't reverse lookup. Any legitimate host which doesn't reverse lookup
is misconfigured. Unfortunatly there are too many legit but misconfigured
sites out there.
You can disable the check for a reverse lookup by putting
+allow_unknown
in your file used by
recipient_reject_hosts
This is, of course, in the docs. As is the rational for the default
behavior.
I will produce that summary I promised where I specifically asked people
on this list and another whether they blocked hosts that didn't reverse
lookup in DNS.
-j
--
Jeffrey Goldberg +44 (0)1234 750 111 x 2826
Cranfield Computer Centre FAX 751 814
J.Goldberg@??? http://WWW.Cranfield.ac.uk/public/cc/cc047/
Relativism is the triumph of authority over truth, convention over justice.
--
*** Exim information can be found at
http://www.exim.org/ ***
