Sending SMS seems ok, in fact, pretty much everything looks ok except inbound SMS are not being delivered to any of my endpoints?
That is, an SMS goes out containing an alert, one of the recipients attends and sends back a reply to say they're on it, or they need help, or they need a crew or whatever. The outgoing SMS gets delivered, their reply doesn't get back to my server.
This isn't a single server, it's several different servers, on different IP ranges, with different APIs and keys.
I don't know how to contact anyone who even knows what this stuff is, much less able to look into it.
Anyone got any ideas please?