Using our API with an e-mail sender software you can set it to send e-mails when you loose the main power and the OpenUPS is on batteries. Check the openups state variable from the api. Please see the included example:
switch (state)
{
case 1: printf("State: Battery ");break;
case 2: printf("State: VIn ");break;
case 3: printf("State: only USB ");break;
default: printf("State: Error ");