[pattycake]

I have done a LOT of researching on this. The problem is on the vbulletin side.
Look at this header from my site - it is the result of one member sending another a message. And yes, the actual emails have been changed.

Return-path: <ktmtalk_XXXX@ktmtalk.com>
Received: from localhost ([::1]:38730)
by server.ktmtalk.com with esmtp (Exim 4.82)
(envelope-from <ktmtalk_XXXX@ktmtalk.com>)
id 1WhKcS-0003zK-LQ
for copeXXXX@aol.com; Mon, 05 May 2014 11:15:52 -0400
Date: Mon, 05 May 2014 15:15:52 +0000
To: copeXXXX@aol.com
From: "ridenazi @ KTMTalk.com - The Absolute BEST KTM resource on the planet" <ktmXXX@yahoo.com>
Sender: ktmtalk_XXXX@ktmtalk.com
Message-ID: <20140505151548.74e58578d1e4@ktmtalk.com>
MIME-Version: 1.0
Content-Type: text/plain; charset="ISO-8859-1"
Content-Transfer-Encoding: 8bit
X-Priority: 3
X-Mailer: vBulletin Mail via PHP
Subject: ktm300 4 sale

Ok, now look at the FROM. It shows:
"ridenazi @ KTMTalk.com - The Absolute BEST KTM resource on the planet" <ktmXXX@yahoo.com>

It's [SAYS] that it's FROM ktmXXX@yahoo.com when in reality, it is from MY server. vBulletin does the "from" this way so that the "receiver" of the message can hit reply and have it go to the original "sender".

So THAT is the problem... the header says it is from ktmXXX@yahoo.com when it's actually from my server (ktmtalk.com).

To confirm, on your next "bounced email", go look at the headers, specifically the FROM. If the entire "from" shows ANYTHING except your mail server, it will fail DMARC.

btw: AOL and gmail have both started using this "standard".

-pat-