On 2013-05-07 17:36:49 -0500, /dev/rob0 wrote:
> I'm going to take this chance to pipe into this thread that I am
> confused about Vincent's issue. He says that the client which lacked
> PTR (the one run by a Debianista) was not a mail exchanger, or not
> exchanging mail.
>
> Why, then, would reject_unknown_reverse_client_hostname be an issue?
> Obviously one must never apply this against one's own submitting
> users. Or was Vincent confused about the distinction between mail
> exchanging clients and submission clients?
I'm not sure about your terminology. When I hear "mail exchanger",
I think about "MX" and a machine pointed to by a MX record. At
least this is what I get when searching for "mail exchanger" on
Google.
Here, I meant that the machine isn't related to a MX record. The
two Received line about the sender are:
Received: from carotte.tilapin.org (unknown [95.138.72.61])
by ioooi.vinc17.net (Postfix) with ESMTPS id EFA4959
for <vinc...@vinc17.net>; Tue, 2 Oct 2012 03:15:23 +0200 (CEST)
Received: from [192.168.1.60] (ident=taffit)
by carotte.tilapin.org with esmtpsa (TLS1.0:RSA_AES_256_CBC_SHA1:32)
(Exim 4.72)
[...]
It (carotte.tilapin.org) seems to be a machine on a private network
hosting a MSA.
Also, carotte.tilapin.org resolves to a different IP, but perhaps
the IP has changed since Oct 2012. In both cases, the IP addresses
don't have a PTR. But the user can't do much except by asking his
ISP to add one. If the ISP is like the big ones in France, they
will ignore such requests if they don't some from a majority of
customers. :(
> On Tue, May 07, 2013 at 03:12:58PM -0500, Stan Hoeppner wrote:
> > On 5/6/2013 6:54 PM, /dev/rob0 wrote:
> > > FCrDNS itself is not just a best practice, it is a
> > > requirement.
> >
> > It is preferred, but optional, not required. If it was a
>
> I was speaking in a functional sense. In the real world, you either
> have FCrDNS for your outbound, or you have massive deliverability
> issues.
Perhaps for IPv4 (but this depends: some people send mail to a few
restricted people). If only the IPv6 address lacks a PTR, this is
probably not true, at least in France, where the biggest ISP's don't
support IPv6, so that there are no deliverability issues with them.
Only with the few people who have a MX with IPv6 support.
--
Vincent Lefèvre <vinc...@vinc17.net> - Web: <http://www.vinc17.net/>
100% accessible validated (X)HTML - Blog: <http://www.vinc17.net/blog/>
Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)
