Consider the following scenario:
You are running Microsoft Exchange Server 2013 Client Access role and Mailbox role on the same server.
You have set the ExternalURL property on the Exchange ActiveSync virtual directory.
You upgrade the server to a new build of Exchange Server 2013.
In this scenario, the ExternalURL value for the ActiveSync virtual directory is blank after the upgrade. Therefore, the Autodiscover service does not work for mobile device users.
This issue occurs because of a logic defect in code. Specifically, the ExternalURL value for the ActiveSyncVirtualDirectory attribute is set to null.
To resolve this issue, install the following service pack:
2926248 Description of Exchange Server 2013 Service Pack 1
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For more information about how to configure ActiveSync virtual directory, go to the following Microsoft website:
General information about Exchange 2013 Client Access server configurationFor more information about the Set-ActiveSyncVirtualDirectory cmdlet, go to the following Microsoft website:
General information about the Set-ActiveSyncVirtualDirectory cmdlet