POA cannot provision new Hosted Exchange 2013 subscription to a customer, provisioning fails on creating new Global Address List (GAL) entry in Active Directory with the error message 'Active Directory operation failed'.
More detailed diagnostics is provided below:
Task name Provide Exchange hosting for organization (ds_id=43446)
Task description Provide Exchange hosting for organization John Doe DomainService = 10101, SubscriptionId = 1000101
Last execution output
Provisioning request failed. Error in 'SW Managed Exchange.CreateGlobalAddressList'.
Exception calling "Execute" with "3" argument(s): "Active Directory operation failed on AD01.hosting.local. One or more attribute entries of the object 'CN=Microsoft Exchange,CN=Services,CN=Configuration,DC=hosting,DC=local' already exists."
The reason is issue in the Microsoft Exchange 2013, it cannot create more than 1500 GAL entries in Active Directory: http://blogs.technet.com/b/exchange/archive/2013/04/02/released-exchange-server-2013-rtm-cumulative-update-1.aspx#3569688.
You may check how many GALs already created in AD using the following command in the Exchange Management Shell:
The problem is going to be fixed in the Exchange 2013 Cumulative Update 2.
You may contact Microsoft for a custom fix if any.