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Bob,<br>
<br>
To keep information flowing I always white listed the entire OPLIN
ip range on the OPLIN mail servers, so even if you were the most
prolific spammer in history it would have made it through to OPLIN
accounts.<br>
<br>
Slight correction, PTR records are checked against the HELO greeting
from the connecting server. PTR tests really just shows that you
have a static ip, and control over the DNS for that ip, so it cuts
out things like infected desktops. An example email from my gmail
account to <a class="moz-txt-link-abbreviated" href="mailto:jendreka@oplin.org">jendreka@oplin.org</a> looks like this...<br>
<br>
Received: from mail-wi0-f173.google.com (mail-wi0-f173.google.com
[209.85.212.173]) by barracuda.oplin.org with ESMTP id
LKn2Dz52N1n2Bhpk for <a class="moz-txt-link-rfc2396E" href="mailto:jendreka@oplin.org"><jendreka@oplin.org></a>; Fri, 29 May 2015
07:55:29 -0400 (EDT)<br>
<br>
mail-wi0-f173.google.com
is how Google identified itself to my Barracuda, and
mail-wi0-f173.google.com is listed as the PTR for 209.85.212.173, so
they're set. The record looks like this...<br>
<br>
173.212.85.209.in-addr.arpa. 21599 IN PTR
mail-wi0-f173.google.com.<br>
<br>
If you'd like you can have your server send me a test message at
<a class="moz-txt-link-abbreviated" href="mailto:jendreka@oplin.org">jendreka@oplin.org</a>. I'll look through the headers and we'll get a
PTR configured for it. By your logs the helo is going to start with
"staffweb", but the full helo needed isn't usually written into the
transaction logs. The ip seems to be 66.213.124.227.<br>
<br>
The anti spoofing record you were probably thinking of is a SPF
record. SPF records are created as TXT records in DNS and list out
the various ips that are allowed to send with a given domain in the
"From" field. A SPF record that states only OPLIN ips are allowed to
send mail with oplin.org in the From field would look like this...<br>
<br>
<meta http-equiv="content-type" content="text/html;
charset=windows-1252">
oplin.org. IN TXT "v=spf1 ip4:66.213.0.0/17 -all"<br>
<br>
Let me know if anyone needs clarification. <br>
<pre class="moz-signature" cols="72">Karl Jendretzky
IT Manager - Ohio Public Library Information Network
(614) 728-1515
<a class="moz-txt-link-abbreviated" href="mailto:karl@oplin.ohio.gov">karl@oplin.ohio.gov</a></pre>
<div class="moz-cite-prefix">On 05/28/2015 01:12 PM, Bob Neeper
wrote:<br>
</div>
<blockquote cite="mid:55674C8B.7070309@gmail.com" type="cite">FWIW
<br>
<br>
We have been running eTicket on an internal server for quite a
while.
<br>
Even though a 10.x.x.x it was able to send emails to our OPLIN
accounts.
<br>
<br>
Now we have 1and1 service, which ignores the emails. gmail accepts
them.
<br>
<br>
A log (for eTicket messages) on the server shows:
<br>
<br>
2015-05-27T14:06:54.092279-04:00 StaffWeb postfix/smtp[23851]:
C40684393F: to=<a class="moz-txt-link-rfc2396E" href="mailto:bob@yourcl.org"><bob@yourcl.org></a>, relay=mx01.1and1.com
<br>
[74.208.5.21]:25, delay=0.29, delays=0/0/0.28/0, dsn=4.0.0,
status=deferred (host mx01.1and1.com[74.208.5.21] refused to talk
to
<br>
me: 554-perfora.net (mxeueus004) Nemesis ESMTP Service not
available 554-No SMTP service 554 invalid DNS PTR resource record,
<br>
IP=66.213.124.227)
<br>
<br>
2015-05-27T14:06:55.242391-04:00 StaffWeb postfix/smtp[23850]:
C27AE43942: to=<a class="moz-txt-link-rfc2396E" href="mailto:neeperro@gmail.com"><neeperro@gmail.com></a>, relay=gmail-smtp-
<br>
in.l.google.com[74.125.201.27]:25, delay=1.4,
delays=0.01/0/0.48/0.95, dsn=2.0.0, status=sent (250 2.0.0 OK
1432750004
<br>
th17si142130icb.46 - gsmtp)
<br>
<br>
1and1 error message information shows:
<br>
<br>
550 No SMTP Service
<br>
The IP Address of the email Server you use is not allocated a
domain name in the domain name service (DNS).
<br>
Please contact your Administrator to add the domain name to the
domain name service.
<br>
<br>
550 Bad DNS PTR resource record
<br>
The e-mail server you are using employs is using a dynamic IP
address.
<br>
To deliver your e-mail please use the Smarthost of your provider
to deliver e-mails.
<br>
<br>
<br>
So it seems (I think)
<br>
Many email servers will check for PTR records to ensure mail is
not spoofed. PTR's are basically reverse DNS.
<br>
If they receive an email from w.x.y.z from <a class="moz-txt-link-abbreviated" href="mailto:somebody@foo.com">somebody@foo.com</a>, they
do a look up on w.x.y.z to ensure it is really foo.com.
<br>
If not, they ignore the email.
<br>
<br>
And our internal only server doesn't meet requirement for 1and1,
while google doesn't care.
<br>
<br>
Bob
<br>
<br>
</blockquote>
<br>
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