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.

Thanks, I didn't know that.

>> 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.

I've done none of the above. I've been using Twilio for 3 years and this is the first time I've ever had an SMS rejected. I don't get it.

>> I think voip.ms only allows person-to-person traffic. Try registering a number there and sending the same message that got blocked.

I'll give that a try.

I've found sending from toll free numbers like 1-888 reduced filtering also. Only costs like a dollar or 2 a month extra.

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.

So it is quite possible that your message exceeded the threshold with "Verizon" in it, but was just below the threshold without "Verizon".

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?