PLUG-discuss digest, Vol 1 #1988 - 11 msgs

[Doug Winterburn]

> Message: 1
> Date: Sun, 3 Mar 2002 13:42:52 -0700
> From: "J.Francois" <frenchie@magusnet.com>
> To: plug-discuss@lists.plug.phoenix.az.us
> Subject: Re: DNS MX and AOL
> Organization: MagusNet, Inc. Design * Develop * Integrate
> Reply-To: plug-discuss@lists.plug.phoenix.az.us
> 
> See below.
> 
> On Sun, Mar 03, 2002 at 11:58:07AM -0700, Doug Winterburn wrote:
> > I run sendmail on my firewall (for the past 3 years) and have been
> > having trouble receiving emails from AOL users for about two weeks.  My
> > ISP has two MX records for my domain, one for my firewall with priority
> > 10, and one for their mail server as a backup with priority 100.  The
> > one thing that I seem to recall is configured incorrectly is the MX
> > record for my sendmail server points to a DNS CNAME record rather than
> > an A record.
> >
> > The failure symptoms are intermittent bounced email to AOL users
> > attempting to send email to my domain with an error message indicating
> > that the AOL mail delivery agent and my ISP's mail server session timed
> > out.  I haven't had any problems for other than AOL users and this has
> > only been happening for about the past two weeks.
> >
> > Is it possible that AOL is attempting to contact my ISP's mail server
> > rather than my email server because of this CNAME vs A record
> > configuration on my ISP's DNS server?
> >
> > Any ideas?
> >
> > Thanks,
> >
> > -Doug WInterburn
> 
> Prevailing wisdom says an MX should never point to a CNAME.
> See: RFC-974 and RFC-1912 and RFC-1034
> Note that these RFCs are not exactly clear when looked at together
> and could be interpreted as meaning that it doesn't matter.
> 
> The resolver library in *NIX ( don't know about WIN ) should be
> able to do a CNAME to MX to A record lookup if your ISP has the
> relevant DNS entries for the CNAME both for A and PTR records.
> What MTA are they using for the MX on the ISP side?
> 
> It could also be as simple as your ISP having an overloaded mail server
> and one of the MTAs is simply timing out during delivery.
> How about the full header from the bounce message.
> That would help a lot.

Jean,

My ISP is Speedchoice (sprint broadband) and am not sure what MTA they
use.  Since only AOL email users are having problems getting through to
me, The questions I have are 1) why isn't AOL trying my sendmail first
before going to my ISP's server, and 2) why do AOL's server get this
error when talking to speedchoice when no other MTA's seem to?  Anyway,
her's the relavent part of one of the bounce messages (not much help):

The original message was received at Fri, 1 Mar 2002 17:52:36 -0500
(EST)
from root@localhost


   ----- The following addresses had permanent fatal errors -----
<doug@winterburn.net>


   ----- Transcript of session follows -----
<doug@winterburn.net>... Deferred: Connection timed out with
mail.phoenix.speedchoice.com.
Message could not be delivered for 1 day
Message will be deleted from queue
Reporting-MTA: dns; imo-r09.mx.aol.com
Arrival-Date: Fri, 1 Mar 2002 17:52:36 -0500 (EST)


Final-Recipient: RFC822; doug@winterburn.net
Action: failed
Status: 4.4.7
Remote-MTA: DNS; mail.phoenix.speedchoice.com
Last-Attempt-Date: Sat, 2 Mar 2002 18:07:50 -0500 (EST)
Received: from Piaccess@aol.com
        by imo-r09.mx.aol.com (mail_out_v32.5.) id o.4d.1a06b1b8 (4197);
        Fri, 1 Mar 2002 17:52:36 -0500 (EST)
Return-path: <Piaccess@aol.com>
From: Piaccess@aol.com
Message-ID: <4d.1a06b1b8.29b16033@aol.com>
Date: Fri, 1 Mar 2002 17:52:35 EST
Subject: Remember When
To: ebcrane@juno.com, rdbj@ucnsb.net, buckandjoyce@msn.com,
Fiedlerjc@aol.com,
        Jimmyp421@home.com, jhollida@twcny.rr.com, jkihms@juno.com,
        omappeals@hotmail.com, lkm511@hotmail.com, rinneo@yahoo.com,
        crussell@allianceprecisionindustries.com, newyorktutu@msn.com,
        Rayweishaar@aol.com, doug@winterburn.net
MIME-Version: 1.0
Content-Type: text/plain; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
X-Mailer: AOL 7.0 for Windows US sub 118



 Subject: Thought you might enjoy reading this.



Thanks,

-Doug Winterburn

PS:  Going to contact Speedchoice support (such as it is) and try to get
them to correct the DNS MX config.