Sign in with Microsoft
Sign in or create an account.
Select a different account.
You have multiple accounts
Choose the account you want to sign in with.


Consider the following scenario:

  • You deploy Exchange Server 2010 Service Pack 3 (SP3) in two Active Directory sites (Site A and Site B). Both sites have different internal URLs for Exchange Web Services (EWS).

  • You install Update Rollup 19, Update Rollup 20, or Update Rollup 21 for Exchange Server 2010 SP3 on both sites.

  • You create a room mailbox, and then you set up a service account that has impersonation configured in Site A.

  • In EWS Editor, you set the Service URL to the FQDN EWS URL for Site B's Client Access server (CAS), and then you set the credential of the service account by selecting the Use the following credentials instead of the default Windows credentials check box. Then, you select the Check if using EWS Impersonation check box, select SmtpAddress in Id Type, input the SMTP address of the room mailbox, and then click OK.

  • After you connect to the room mailbox that uses impersonation, you try to expand the folders.

In this scenario, you cannot expand the folders. Additionally, you receive an "http 500 internal error" error message.


To fix this issue, apply Update Rollup 22 for Exchange Server 2010 SP3.


To work around this issue, do one of the following:

  • Connect to the same site as the resource rooms for EWS calls to avoid the proxy calling to a different CAS.

  • Enable the resource room's Active Directory account. For more information, see Enable AD-Account.


Microsoft has confirmed that this is a problem in Update Rollup 19, Update Rollup 20, and Update Rollup 21 for Exchange Server 2010 SP3.


For more information about EWS Editor impersonation, see Testing Impersonation Permission with EWS Editor.

Learn about the terminology that Microsoft uses to describe software updates.

Need more help?

Want more options?

Explore subscription benefits, browse training courses, learn how to secure your device, and more.

Communities help you ask and answer questions, give feedback, and hear from experts with rich knowledge.

Was this information helpful?

What affected your experience?
By pressing submit, your feedback will be used to improve Microsoft products and services. Your IT admin will be able to collect this data. Privacy Statement.

Thank you for your feedback!