title: How to diagnose and fix routing issue with domain-hosted email
body: <p>This is not an EE question, though the client does have an EE website :). I just tagged it this way to get the smart folks in the community to see my question.</p>
  
  <p>I have a client who used to have their email and website hosted separately. They were setup with Exchange Server service from one host and regular linux webhosting with another. The way they had it set up initially was their domain was pointed at their webhost and the MX record was forwarded to their Exchange host.  The company from which they were getting the Exchange service through also offers webhosting, so they decided to consolidate. The website was moved to the new account - no problem.  Then we pointed the entire domain, from the registrar level, to the host that had previously hosted only their email. That's where the problems set in.</p>
  
  <p>Now, some emails go through, and some don't - seemingly without any specific pattern. You can send the same email to the same address several times, and some go through and others bouceback.  The ones that bounceback offer some clues - they mentioned the mail server as mail.clientdomain.com - which is not right, as with their Exchange hosting, there is a separate dedicated domain for Exchange.</p>
  
  <p>What it seems like is that in turning on the webhosting component of their account, two things happened - first, a setup of mail.clientdomain.com seems to have been undertaken even though it's not needed.  And then secondly, internal to the hosting architecture, their DNS server is sometimes routing mail through the Exchange server and sometimes running it through mail.clientdomain.com (which of course doesn't work because there are no users set up there, and results in the bounce back).</p>
  
  <p>The main trouble I'm having is telling the host WHAT to fix. I provide them with the symptoms we're experiencing and what I think may be going on, but I'm not well versed in server setup so I can't provide any more direction than i have.  I'm hoping someone out there can give me some guidance on how I can run some tests to see where mail at my client's domain is being routed and therefore provide the host with some specific direction as to where the breakpoint is - because thus far, they have been unable to fix the problem.</p>
  
  <p>Thanks all!</p>
  
  <p>UPDATE: HERE'S WHAT THE RETURNED MESSAGES LOOK LIKE MOST RECENTLY:</p>
  
  <p>Hi. This is the qmail-send program at plesk-vl4.ihost-web.com.
  I'm afraid I wasn't able to deliver your message to the following addresses.
  This is a permanent error; I've given up. Sorry it didn't work out.</p>
  
  <p>--- Below this line is a copy of the message.</p>
  
  <p>Return-Path: 
  Received: (qmail 1553 invoked from network); 2 Nov 2012 07:26:47 -0400
  Received: from smtp137.ord.emailsrvr.com (173.203.6.137)
   by webmail.plesk-vl4.ihost-web.com with (DHE-RSA-AES256-SHA encrypted) SMTP; 2 Nov 2012 07:26:47 -0400
  Received: from localhost (localhost.localdomain [127.0.0.1])
      by smtp10.relay.ord1a.emailsrvr.com (SMTP Server) with ESMTP id 9803F370097;
      Fri,  2 Nov 2012 07:29:55 -0400 (EDT)
  X-Virus-Scanned: OK
  Received: by smtp10.relay.ord1a.emailsrvr.com (Authenticated sender: jean-AT-qbmarketing.com) with ESMTPSA id 4BD76370091;
      Fri,  2 Nov 2012 07:29:55 -0400 (EDT)
  From: Jean St Amand 
  Content-Type: multipart/alternative; boundary="Apple-Mail=_25EBC7EF-43BA-46B6-94CE-143CA2B87CC2"
  Subject: another test email the morning of Nov 2
  Date: Fri, 2 Nov 2012 08:32:20 -0300
  Message-Id: &lt;56ED44AF-6B20-4627-A53D-1A27E055C2DE@qbmarketing.com>
  To: Steve 
  Mime-Version: 1.0 (Mac OS X Mail 6.2 (1499))
  X-Mailer: Apple Mail (2.1499)</p>
  
  <hr>
  
  <p>The host has said that the system is setup correctly and that the bounce backs are the result of "auto-complete" in our mail programs. But auto-complete only fills in an email address that's been used in the past, not the routing used to get to that destination, isn't that right? If auto-complete played a role in routing, wouldn't everyone run into trouble every time they change web hosts? I've never had any trouble switching hosts in the past, so I find it a bit hard to believe that it's the sender's mail program that's the problem - especially since sometimes the messages do go through, but most often that don't.</p>