Outlook 2003 is unresponsive when managing Delegates with Exchange 2010

Here’s something I came across while helping a colleague out with an unusual issue they were seeing against a customer’s Exchange 2010 environment with Outlook 2003 clients. We spent a fair bit of time looking into the issue and determined that it affected Outlook 2003, and Outlook 2007 SP2 and below (unless this patch was applied).

Confirmation came from Microsoft PSS that this was an issue, however it’s not something that had been publically documented. After talking to Henrik Walther I was glad to find that I wasn’t the only person out there to have seen this, though, however it’s fair to say it’s unusual that this would be a major issue. Here’s a little more on the problem:

When reviewing or modifying delegate information via Tools>Options and choosing the Delegates tab, Outlook 2003 may exhibit some or all of the following symptoms:

  • Choosing the Delegates tab causes Outlook 2003 to stop responding for upwards of 30 seconds to 2 minutes before displaying information.
  • When saving delegate information, Outlook 2003 stops responding for upwards of 30 seconds to 2 minutes before closing the Options window.
  • The message "Outlook is trying to retrieve data from the Microsoft Exchange Server" pop-up notification is displayed to the user.

You’ll see this in action in the video below:

Unable to display content. Adobe Flash is required.
A long video showing what should be a 30 second process

In previous versions of Exchange Server, the Outlook Client talked directly to a Global Catalog server after a DSProxy referral. In Exchange Server 2010, the Client Access Service runs the Address Book Service which provides the NSPI endpoint that Outlook clients connect to for accessing directory information.

This issue is caused by the method Outlook 2003 requests data from the Address Book Service on the Client Access Server. The issue is corrected in current versions of Outlook 2007 and 2010, but will not be corrected in Outlook 2003.

The workaround to this issue is to limit which users should be delegates on mailboxes, and grant general calender sharing permissions via the following method, which is also applicable to other Outlook folders.

  1. Right-click the Calendar folder, and then click Properties.
  2. Click the Permissions tab.
  3. Click Add.
  4. Click the name of the user who you want to grant permissions to, click Add, and then click OK.
  5. In the Name box, click the user name, and then choose the permission level, for example Editor in the Permission Level box.
  6. Click Apply, and then click OK.

There is a way to force Outlook 2003 to contact a Global Catalog server directly – this was published in the KB article KB319206, How to configure Outlook to a specific global catalog server or to the closest global catalog server. In our customer’s environment, MS suggested it’s use, and theoretically it should be similar to an Exchange client access server running on a AD DC/GC (which is supported). However, given the article says it should never be used in an Exchange 2010 environment I would stay away from it unless specifically advised otherwise by Microsoft.

I’ve updated the TechNet Wiki article Concern: Is Having Outlook 2003 Clients Going to Prevent Me from Deploying Exchange 2010? with this information.