Update 1: The fix for this issue has been released in the 12.1.2 Update for Office 2008 for Mac. See 'Improvements for Microsoft Entourage 2008 for Mac' section in KB 956344.

Update 2: The fix for a subsequent 'CNAME' entry issue discussed in the comments section of this blog post has been released in the 12.1.3 Update for Office 2008 for Mac. See 'Improvements for Microsoft Entourage 2008 for Mac' section in KB 958267.

In this post I wanted to quickly provide an update on an ongoing issue with some specifics to make sure our customers are well informed on its current status.

Issue
After installing Office 2008 for Mac Service Pack 1 (SP1) when Entourage 2008 users connect to their mailbox on an Exchange 2007 Server, they may see an error like this (you can substitute 'contoso' in the screenshot below with your own root domain):

If you click on 'OK', Entourage will continue to work and you won't see this error message again until the end of that session when you close Entourage. Clicking on 'Cancel' you may end up in 'Not Connected' state with your Exchange account. This error may also come up when:

1. You try to configure your Exchange account using 'Account Setup Assistant' which now uses Autodiscover Service on Exchange 2007 to automatically configure your account or

2. You use any 'Exchange Web Services' based feature in Entourage 2008, like OOF Assistant, Free/Busy Info pull-up, etc. as they also utilize Autodiscover feature or

3. Entourage tries to talk to Autodiscover Service while its running connected to your mailbox to see if any updates were made to Autodiscover Service on server side by your Exchange Administrator, this happens automatically in the background based on a pre-set interval which cannot be modified by user

Cause
This happens as Entourage 2008 tries to establish a secured connection to the first of the 2 default addresses (URLs) in its attempt to contact the Autodiscover Service on your Exchange 2007 Server. This is explained in the Autodiscover Whitepaper, see 'How the Autodiscover Service Works with Clients' section. Most organizations using Exchange 2007 do not publish Autodiscover Service thru the first URL mentioned over there, i.e. 'https://contoso.com/autodiscover/autodiscover.xml', rather they use the other URL, i.e. 'https://autodiscover.contoso.com/autodiscover/autodiscover.xml'. When Entourage finds an error (mostly its 'Common Name' mismatch) with the certificate published at the root of your domain (if there is one, many organizations do, but 'Common Name' on that certificate is 'www.contoso.com', not just 'contoso.com' and Autodiscover Service is not published thru that URL), it displays the above error. It does not move silently to try the other possible URL. Clicking 'OK' on above error makes it exactly do that and thus it finds the Autodiscover Service responding on the other URL and everything then works fine from there.

This issue can also happen in Entourage 2008 if Autodiscover Service is not configured properly as per the guidelines in Autodiscover Whitepaper. See 'Note' below on how to quickly check to see if Autodiscover Service is properly configured and published for users.

Resolution
Microsoft is working to release a fix for this issue in an update for Entourage 2008 but a final release date is not available yet. I plan to update this post with new information in this regard when it becomes available.

Note
We need to make sure that when Entourage looks for Autodiscover Service, the related URL as mentioned above in 'Cause' section is configured and published to respond to those requests. A quick way is to look up the A Record (a type of DNS record which is used to map a hostname or URL to the IP Address of the host) which you will have to register with your DNS provider.

A Working Example:
For Microsoft, the Autodiscover Service is configured and published at 'https://autodiscover.microsoft.com/autodiscover/autodiscover.xml', you can look it up using this URL in your browser:

http://codeflux.com/exec/tools/?method=nslookup&query=autodiscover.microsoft.com&type=A

You will see an IP Address is mapped to the URL for Autodiscover Service to respond to incoming requests.

Now, if I go and hit the URL for Autodiscover Service in my browser, i.e. 'https://autodiscover.microsoft.com/autodiscover/autodiscover.xml'

I will get a window to enter my user credentials (domain\username & password) and after that I will see the following lines in the main browser window:

<?xml version="1.0" encoding="utf-8" ?>
- <Autodiscover xmlns="http://schemas.microsoft.com/exchange/autodiscover/responseschema/2006">
- <Response>
- <Error Time="10:29:57.7332076" Id="59171512">
    <ErrorCode>600</ErrorCode>
    <Message>Invalid Request</Message>
    <DebugData />
</Error>
</Response>
</Autodiscover>

The response above says 'Error 600, Invalid Request' as the Autodiscover Service URL is not supposed to be accessed thru a browser. This is an expected response in this scenario and confirms the proper configuration and publishing of Autodiscover Service.

A Non-Working Example:
Let's use Contoso as a non-working example, the Autodisover Service should be configured and published at 'https://autodiscover.contoso.com/autodiscover/autodiscover.xml', if you look it up using this URL in your browser:

http://codeflux.com/exec/tools/?method=nslookup&query=autodiscover.contoso.com&type=A

You won't find an IP Address mapped to the URL for Autodiscover Service, instead you will see an error there saying 'server can't find autodiscover.contoso.com'.

Parts of Hyperlink After Ampersand Sign Are Stripped in Entourage 2008

SSL Warning Issue in Entourage 2008