Twilio CEO's open letter to AT&T about net neutrality
medium.com
medium.com
If you want to send messages in bulk, the process is, get a short code, pass carrier testing, then your messages are received. Twilio needs to implement something like complaint feedback, similar to what AWS does for email. If someone reports a message back to code 7726 (SPAM), there's no way to know that. Twilio is big enough that they could work with carriers instead of demanding carriers open the gates to any/every message.
https://blog.cloudmark.com/2014/02/13/sms-phishers-exploit-t...