So I was sending an SMS to my friend using Twilio. And it got rejected as violating carrier guidelines. It was about masks, not even controversial. I tried to send my friend a copy/paste of the twilio error message and this was rejected as violating carrier guidelines.<p>--edit to clarify rejected/accepted messages<p>This gets rejected: "(Error: 30007) Carrier violation. Your message content was flagged as going against Verizon carrier guidelines."<p>This does not get rejected: "(Error: 30007) Carrier violation. Your message content was flagged as going against carrier guidelines. Verizon"<p>This gets rejected: "(Error: 30007) Verizon Carrier violation. Your message content was flagged as going against carrier guidelines."<p>The only difference is adding the word Verizon in various places.<p>And by the way Verizon, why is a Twilio error message considered harmful enough to filter?
All traffic passing through Twilio is categorized as application-to-person traffic. If you haven't registered your brand, been assigned a trust score, and registered your specific number with a specific a2p campaign, you'll be subjected to heavy filtering.<p>I'm not positive, but I think voip.ms only allows person-to-person traffic. Try registering a number there and sending the same message that got blocked.
In general A2P messages are subjected to harsh anti-spam filters. SMS spam filters work similar to email spam filters - i.e. they use various Bayesian rules to calculate spam score and classify the message as spam if that score is above threshold.<p>In addition, SMS filters are more strict than email filters - because they have a lot less text to work with and also SMS spam is more annoying than email spam. The downside is that there are more false positives than in case of emails.<p>So it is quite possible that your message exceeded the threshold with "Verizon" in it, but was just below the threshold without "Verizon".
>> Why are there rules about the content of text messages at all?<p>I have no idea. What is disturbing to me is the arbitrary stuff Verizon is filtering. Seriously, what is so controversial about a Twilio error message?
Why are there rules about the content of text messages at all? Do we need any rules besides (1) no unsolicited bulk texts, i.e., spam, and (2) no texting people who have told you not to text them anymore?
Likely it's to cut down on scams. Does the error also happen when you send the text message with, say, "Verizon" tacked on the end? Or somewhere in the middle of the sentence?