> It's more effective to spend the money on SMS messages. Mobile
> providers are forced to use very aggressive anti spam measures, which
> can add significant delays in message delivery.
Recommendations on software and modems?
Easy enough to build, here's one I made earlier
ebay/old Sun X1, serial gsm modem, qpage = OOB alarms
Sun X1s are cheap, low power and have good management already
so you can throw them in remote places