How to fix Mac OS X Snow Leopard when it stops synchronizing with a hosted Exchange email account.

If you are synchronizing your Exchange 2007 Acocunt with your Mac OS X Snow Leopard system’s Mail, Calendar and Address Book apps, you can run into the problem that synchronization stops working because your hosted Exchange provider has moved the Exchange Web Services from one server to another. This can happen when Exchange is upgraded, for example and normally does not affect mail delivery in the case of Outlook or Entourage as mail clients, because they run Exchange AutoDiscover on launch to verify the URLs used are up-to-date. This mechanism actually adds a lot of flexibility to hosting email services.

Unfortunately, Mac OS X Snow Leopard’s built in email client does not run AutoDiscover except on account creation. So the easiest fix is to delete and re-create your email account, but that’s sort of a crude approach, triggering a re-synchronization of the entire mail account which can be quite cumbersome and time-consuming.

Here is a guide how to manually find and update the server name of the Exchange Web Services server that your hosted Exchange account is using in your Mac’s Mail app.

First navigate to https://www.testexchangeconnectivity.com/, a site that allows you to manually run AutoDiscover against your Exchange account.

Select “Outlook AutoDiscover” from the first page and click on “Next”.

On the next page, enter your email account information. The password is needed as Exchange servers require user authentication in order to perform AutoDiscover. Should the test fail because the server doesn’t have a valid SSL certificate, select “Ignore Trust for SSL”.

If the test succeeds, expand the “Test Details” section of the test results page and locate the returned AutoDiscover XML file.

Additional Details

AutoDiscover Account Settings

XML Response

<?xml version=”1.0″?>

<Autodiscover…

<Response…

…

<EwsUrl>https://newserver.sample.com/EWS/Exchange.asmx</EwsUrl>

Find the <EwsUrl> tag and note the Exchange Web Services server name. Note that this may be a completely different server than you are using to access Exchange via IMAP and SMTP.

Now open the Mail App and configure your account, adding the server name under “Internal Server” and “External Server” which should be the same if you are not connecting to an Exchange server in an Intranet/Domain.

Then open the Address Book app and do the same in the “Server Settings” tab of the “Accounts”-section of its preferences. You can also verify the “Server Path”s against the response from AutoDiscover.

Finally open the Calendar application and again, in the “Server Settings” tab of the “Accounts”-section of its preferences, update the Server names and verify the Server paths.

Restart all Mail, Calendar and Address Book and verify that they connect to your Exchange account again.