Legrand CRM v6.5 uses the Messagemedia service to send SMS messages directly from the desktop client. 

To use this feature you must first obtain an account with Messagemedia, who will supply you with an Account ID and password to interface with their service.

Once that information is available, activate the SMS feature by logging into Legrand CRM v6.5 using an administrator level user account and follow the steps on the attached document.