Try the Exchange Remote Connectivity Analyzer service beta
Verify that your Internet facing services are setup and configured properly with the new Exchange Remote Connectivity Analyzer. With the tool, you can remotely test the Exchange Active Sync, Outlook Anywhere and Inbound SMTP services. Each test simulates the steps that Outlook, a mobile device or Internet e-mail server goes through to connect. For more on the beta of this online tool, see the Microsoft Exchange team blog.
More to come,
Mitch
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