At a quick glance, it seems like anything beyond a fire-and-forget SMS/fax done with Twilio requires a callback. My guess is that Twilio is expecting their cus

At a quick glance, it seems like anything beyond a fire-and-forget SMS/fax done with Twilio requires a callback. My guess is that Twilio is expecting their customers to be able to write a callback and is willing to accept the associated barriers for entry.