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Verizon Rejecting Twilio Error Message as Violating Carrier Guidelines

18 points by another_comment ↗ HN
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.

--edit to clarify rejected/accepted messages

This gets rejected: "(Error: 30007) Carrier violation. Your message content was flagged as going against Verizon carrier guidelines."

This does not get rejected: "(Error: 30007) Carrier violation. Your message content was flagged as going against carrier guidelines. Verizon"

This gets rejected: "(Error: 30007) Verizon Carrier violation. Your message content was flagged as going against carrier guidelines."

The only difference is adding the word Verizon in various places.

And by the way Verizon, why is a Twilio error message considered harmful enough to filter?

13 comments

[ 0.17 ms ] story [ 50.6 ms ] thread
josephcsible
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?
toomuchtodo
People don’t want SMS spam anymore than they want car warranty scam phone calls, therefore carrier guidelines exist for SMS messages sent from applications (versus persons).
another_comment
>> Why are there rules about the content of text messages at all?

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?

slater
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?
another_comment
This does not get rejected: "(Error: 30007) Carrier violation. Your message content was flagged as going against carrier guidelines. Verizon"
another_comment
This gets rejected: "(Error: 30007) Verizon Carrier violation. Your message content was flagged as going against carrier guidelines."
another_comment
This gets rejected: "(Error: 30007) Carrier violation. Your message content was flagged as going against Verizon carrier guidelines."
benttoothpaste
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.

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".

minerva23
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.

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.

another_comment
>> All traffic passing through Twilio is categorized as application-to-person traffic.

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.

jrowley
These are relatively new restrictions - have been rolling out since this fall. https://support.twilio.com/hc/en-us/articles/1260800720410-W...

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

minerva23
That's not just anecdotal. The carriers do process short code and toll free traffic differently from regular 10DLC. You don't even need do register an a2p campaign for them.
axiosgunnar
What was the content of the message about masks?