Take a look at our "3CX 911 (Emergency) Notifier". We can send notifications via email, SMS, phone (using text-to-speech), and desktop screen pop. Notifications are sent based on location even with a shared PBX across multiple locations. You create 3CX extension groups that represent locations, and then assign notifications based on extension group membership. And your existing outbound rules will still work too.
Founded in 2005, when VoIP was an emerging technology, 3CX has gone on to establish itself as a global leader in business communications.