When you use Microsoft Outlook to change a distribution group in a multi-tenant Microsoft Exchange Server 2010 environment, Outlook stops responding until you cancel the server request. For Outlook Web App, it also stops responding when you try to change the distribution groups there.
Note The time that this change takes depends on the number of the tenants. The more the tenants, the longer time that it takes.
This issue occurs because the globalAddressListFromAddressBookPolicy parameter is NULL in the GetGlobalAddressList function, and it causes the function looping through all the address lists to find the closest match. Therefore, Outlook or Outlook Web App stops responding.