If you are running Exchange ActiveSync behind a Cisco ASA firewall you may receive Event ID: 1040 in your application event log. The event basically says: The average of the most recent heartbeat intervals [470] for request [Sync] used by clients is less than or equal to [540]. Make sure that your firewall configuration is set to work correctly with Exchange ActiveSync and direct push technology. Specifically, make sure that your firewall is configured so that requests to Exchange ActiveSync do not expire before they have the opportunity to be processed. To resolve this error we can bump up the …