Ask HN: When using Twilio, how do I tell if my SMSes are being carrier filtered?

[reallyeli]

My startup sends SMSes through Twilio. I know from https://support.twilio.com/hc/en-us/articles/223181708-Can-my-Twilio-SMS-Messages-be-Blacklisted-as-Spam- that, if a phone carrier filters my message, I won't necessarily get an error code from Twilio.

In practice, how do you tell if you're being carrier filtered? What circumstances have you observed it happening in? What is a safe line to stay within?

[arrowgunz]

Have you tried using https://support.twilio.com/hc/en-us/requests/new

If not, please use that. Hacker News is not really the place for Product Support.

[reallyeli]

I'm looking for what people's real experiences are. Twilio provides guidelines around this, but they are very conservative and speculative.

If this isn't the place, though, I understand.