RE: RES: RES: Email oddity -- MIDRANGE-L

This looks better. But, I think I was always able to receive emails from BAXTER. Still >seems< to have rDNS issue, according to the spam scanner. But, the top now has the URL and the IP, below (slightly scrubbed). I tried sending an email from work using my work email as sender, to a Cox account. No reject error, so far. So what is with the last line about no rDNS? Also says something about a missing message id header. I am going to look at the headers closely on Monday.

John McKee

Return-Path: <jmckee@xxxxx>
Received: from mail7.wildflower.net (mail7.wildflower.net [24.249.116.47])by mail8.wildflower.net (IceWarp 10.0.7) with ESMTP id YHZ23405 for <jmmckee@xxxxxxxxxxxxxx>; Sat, 14 May 2011 21:10:05 -0500
X-ASG-Debug-ID: 1305425408-285b27820001-bZofqT
Received: from BAXTER.X.X.NET ([1.1.1.1]) by mail7.wildflower.net with ESMTP id Xh88meHhVz2Hh67X for <jmmckee@xxxxxxxxxxxxxx>; Sat, 14 May 2011 21:10:08 -0500 (CDT)
X-Barracuda-Envelope-From: jmckee@xxxxx
X-Barracuda-Apparent-Source-IP: 1.1.1.1
Sender: jmckee@xxxxx
Date: Sat, 14 May 2011 21:09:42 -0500
From: John McKee <jmckee@xxxxx> [+]
MIME-Version: 1.0
To: John McKee <jmmckee@xxxxxxxxxxxxxx> [+]
Subject: Test email 2108
Content-Type: multipart/mixed; boundary="--PART.BOUNDARY.1"
X-ASG-Orig-Subj: Test email 2108
X-Barracuda-Connect: UNKNOWN[1.1.1.1]
X-Barracuda-Start-Time: 1305425408
X-Barracuda-URL: http://24.249.116.47:8000/cgi-mod/mark.cgi
X-Virus-Scanned: by bsmtpd at wildflower.net
X-Barracuda-Spam-Score: 0.24
X-Barracuda-Spam-Status: No, SCORE=0.24 using per-user scores of TAG_LEVEL=2.0 QUARANTINE_LEVEL=1000.0 KILL_LEVEL=3.0 tests=MISSING_MID, RDNS_NONE
X-Barracuda-Spam-Report: Code version 3.2, rules version 3.2.2.63764Rule breakdown below pts rule name description ---- ---------------------- -------------------------------------------------- 0.14 MISSING_MID Missing Message-Id: header 0.10 RDNS_NONE Delivered to trusted network by a host with no rDNS
Message-Id: <20110515021009.0BBEF1196E7A@xxxxxxxxxxxxxxxxxxxx>

-----Original message-----
From: "Dennis Lovelady" iseries@xxxxxxxxxxxx
Date: Sat, 14 May 2011 02:46:53 -0500
To: "'Midrange Systems Technical Discussion'" midrange-l@xxxxxxxxxxxx
Subject: RE: RES: RES: Email oddity

Loosely related: There are weird times that I can't access my webmail.
The error I get is that the site does not exist. Wait a few minutes,
and all is well. Happens a couple of times a month. Is this related
to DNS changes?

John McKee

It can be. And that can be because you cannot reach your DNS (more likely)
or because of upstream problems. Or it can be that the server has gone
offline for whatever reason. The browser messages are usually somewhat
helpful in identifying the correct cause, unless they are set to "friendly
(meaning uninformative) messages."

Next time it happens, go to a command line and enter:
nslookup server.domain.name

You should be presented with the DNS, or with something informative.

Here's a good result from one of my linux servers:

nslookup www.google.com

Server: 65.32.5.111
Address: 65.32.5.111#53

Non-authoritative answer:
www.google.com canonical name = www.l.google.com.
Name: www.l.google.com
Address: 74.125.47.147
Name: www.l.google.com
Address: 74.125.47.99
Name: www.l.google.com
Address: 74.125.47.103
Name: www.l.google.com
Address: 74.125.47.104
Name: www.l.google.com
Address: 74.125.47.105
Name: www.l.google.com
Address: 74.125.47.106

The first line of response identifies the Name Server that returned the rest
of the information. Now here's what happens if the DNS cannot be reached
(which I simulated by setting false DNS information) :

nslookup www.google.com

;; connection timed out; no servers could be reached

Tying this back to what Ken was saying... Let's say one of the above
servers (. . .106) establishes connection with a mail server, and claims to
be www.google.com (via EHLO www.google.com)
Reverse DNS on the IP address 74.125.47.106 reveals www.l.google.com.

Different, but no matter. Now let's take www.l.google.com and get its list
of addresses (which we did above). Is . . .106 in the list? Yup, so we're
good to go. If .106 had been missing, then some systems (AOL, COX, Comcast,
..) would reject the mail.

Dennis Lovelady
http://www.linkedin.com/in/dennislovelady
--
"As your attorney, it is my duty to inform you that it is not important that
you understand what I'm doing or why you're paying me so much money. What's
important is that you continue to do so."
-- Hunter S. Thompson's Samoan Attorney

--
This is the Midrange Systems Technical Discussion (MIDRANGE-L) mailing list
To post a message email: MIDRANGE-L@xxxxxxxxxxxx
To subscribe, unsubscribe, or change list options,
visit: http://lists.midrange.com/mailman/listinfo/midrange-l
or email: MIDRANGE-L-request@xxxxxxxxxxxx
Before posting, please take a moment to review the archives
at http://archive.midrange.com/midrange-l.