In a Microsoft Exchange Server 2013 environment, when you try to sync your email messages on an ActiveSync device, the device may receive several Ping.FHSyncRequired replies several times a day. This causes the device to become unresponsive until the sync process is complete.
This issue occurs when a non-IPM folder isn't filtered correctly during the ActiveSync process.
Cumulative update information
For Exchange Server 2013
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
Learn about the terminology that Microsoft uses to describe software updates.