On my new Exchange 2013 Servers, I noticed a number of warnings occurring for ActiveSync:

  • The average of the most recent [286] heartbeat intervals used by clients is less than or equal to [540]

Browse to the following location on your exchange Server:

  • C:\Program Files\Microsoft\Exchange Server\V15\ClientAccess\Sync

Open up the Web.Config file with notepad.

Locate the following line item:

  • <add key=”HeartbeatAlertThreshold” value=”540″></add>

I changed my entry to 400 and saved the file. After that you will get an event log that ActiveSync was unloaded and then loaded.

  • <add key=”HeartbeatAlertThreshold” value=”400″></add>

Since the change no more warnings

Hope it helps.

By edward