http://developers.de/blogs/damir_dobric/archive/2015/11/10/iothub-quotas.aspx  When working with IoTHub, you might get following exception: An exception of type 'Microsoft.Azure.Devices.Client.Exceptions.DeviceMaximumQueueDepthExceededException' occurred in mscorlib.dll but was not handled in user code AdditionalenCommunityServer 2008 SP1 (Build: 30619.63)