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I don't think this has anything to do with your VM but more with your Exchange configuration. &nbsp;Have you configured your MX record on dyndns?<br />

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No, as mentioned in the original post, no MX server on the outside dyndns settings (it defaults to mydomain.com).<br />
I use an internal DNS with Active Directory, etc. &nbsp;DYNDS is forwarding all traffic from my domain (mydomain.com) to my external IP, where I have a LAN IP of 10.0.0.1 (rather than the typical 192.168.1.1). &nbsp;I DO have an MX listed in my internal domain. &nbsp;I had already tried adding an MX record to DYNDNS, pointing it to my router's external IP address, and tried with the default (no MX automatically resolves to mydomain.com ) with the port forwarded to my internal IP of the exchange server. &nbsp;No luck.<br />

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With the external MX record on DYNDNS, I do get a different error. &nbsp;After reconfiguring and re-running the test, attempting to deliver to my gmail account, the report I got was:<br />
Area: Mail Acceptance &nbsp;<br />
&nbsp;<br />
Server: EX01 &nbsp;<br />
&nbsp;<br />
&nbsp; Error submitting mail Server: EX01 <br />
&nbsp;Mail submission failed: Error message: Mailbox unavailable. The server response was: 5.7.1 Unable to relay. <br />
&nbsp;<br />
&nbsp; Error submitting mail Server: EX01 <br />
&nbsp;Mail submission failed: Error message: The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.7.1 Client was not authenticated. <br />
&nbsp;<br />

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Take a look here... <a href="http://codebetter.com/blogs/peter.van.ooijen/archive/2006/04/05/Using-localhost-as-mailserver-_2800_5.7.1-Unable-to-relay-for-xxx_2900_.aspx" rel="ugc">http://codebetter.com/blogs/peter.van.ooijen/archive/2006/04/05/Using-localhost-as-mailserver-_2800_5.7.1-Unable-to-relay-for-xxx_2900_.aspx</a><br />
<br />
<br />

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Of course that works for asp.net, using IIS to send mail through a web app.<br />
I'm using Exchange Server 2007.<br />
(btw, sending via localhost doesn't work with all ISP's given the method in that post. &nbsp;Some if not most ISP's will require the smtp client to be set to the Host's SMTP service, due to port blocking,etc in an effort to prevent spamming). &nbsp; <br />

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<div class="content wysiwyg-content">
I've just watched the video from ITIdiots on installing and configuring Exchange 2007.<br />
<br />
Exchange IS delivering email WITHIN the organization (tested with two separate accounts), but is not delivering to or receiving from outside of the network. &nbsp;This suggests that it would be a possible firewall issue. &nbsp;On my router (linksys), I have SMTP (:25) mapped to my Exchange Server.<br />
<br />
I'm using DYNDNS.ORG for my domain resolution to my local router, with no MX server (defaults to my domain).<br />
<br />
When I run the troubleshooting assistant, and generate the report, the error it gives me is: &quot;messages could not be delivered with delivery status notification code '4.4.7'.&quot;<br />
<br />
I use Comcast (residential) for my ISP, so I'm wondering if this has anything to do with the issue. &nbsp;The ITIdiots guys had the same setup, (including VMWare based machines), with the exception of Comcast.<br />
<br />
Is there anything I can do to get this working? &nbsp;I understand the concepts, but first want to ensure that it works, before I continue.
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I've just watched the video from ITIdiots on installing and configuring Exchange 2007.

Exchange IS delivering email WITHIN the organization (tested with two separate accounts), but is not delivering to or receiving from outside of the network.  This suggests that it would be a possible firewall issue.  On my router (linksys), I have SMTP (:25) mapped to my Exchange Server.

I'm using DYNDNS.ORG for my domain resolution to my local router, with no MX server (defaults to my domain).

When I run the troubleshooting assistant, and generate the report, the error it gives me is: "messages could not be delivered with delivery status notification code '4.4.7'."

I use Comcast (residential) for my ISP, so I'm wondering if this has anything to do with the issue.  The ITIdiots guys had the same setup, (including VMWare based machines), with the exception of Comcast.

Is there anything I can do to get this working?  I understand the concepts, but first want to ensure that it works, before I continue.

Exchange 2007 and DynDNS Not Sending or Receiving

Exchange is the server side of a collaborative application product that is part of the Microsoft Server infrastructure. Exchange's major features include email, calendaring, contacts and tasks, support for mobile and web-based access to information, and support for data storage.