Consider the following scenario:
You have a Microsoft Exchange email account that has the DevicePasswordEnabled policy enabled. This means that you must use a device password if you access the Exchange account on a device.
On a Windows RT-based device (such as a Surface RT device), you add the Exchange account to the mail app.
You set up the device so that it does not require a password.
Note When the Users must enter a user name and password to use this computer check box in the User Accounts item in Control Panel is not selected, no password is required when you sign in to the device.
You restart the system and then start the mail app.
In this scenario, you can unexpectedly access the Exchange email account without having to enter password.
This issue may also occur on Windows 8-based devices that are not in a domain environment.
To resolve this issue, install update rollup 2845533. For more information about how to obtain this update rollup package, click the following article number to view the article in the Microsoft Knowledge Base:
2845533 Windows RT, Windows 8, and Windows Server 2012 update rollup: June 2013 After update rollup 2811660 is applied, the Users must enter a user name and password to use this computer check box is disabled in this scenario.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For more information about Exchange ActiveSync (EAS) policies, click the following article number to view the article in the Microsoft Knowledge Base:
2823900 Supported Exchange ActiveSync policy parameters in Windows 8 and RT
For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:
824684 Description of the standard terminology that is used to describe Microsoft software updates