Remote clients aren't communicating with SEPM

In our company we have many remote users.  They have the latest SEP client installed on their laptops.  The SEP manager doesn't appear to be communicating with the remote clients.  While logged into a remote client I see that the virus definitions are up to date but when I log itno the manager I see it is out of date.  As soon as the client connects to VPN then the manager is updated.  How do I get the client to communicate with the manager besides connecting to the VPN?