[zachrose]

I’ve been developing SMS chatbots and using my T-Mobile phone for testing. They will also drop messages that contain URLs, although the rules for which TLDs are allowed are hard to reverse engineer, much less rationalize. Last I remember, .club URLs are blocked, .com is allowed, and bit.ly is allowed.

[foob]

I recently ran into this sort of filtering when trying to share an AI Dungeon .link URL with a friend. It's kind of crazy that entire TLDs are blocked without any indication or warning.

[vincentmarle]

Hmm I suspect this could be related to Branch links, because their default deep link domain is app.link

[willvarfar]

Tangent: tell us about your dungeon! How does it work, are you happy with it etc? Links you can share?

Show HN of course!

[ta1234567890]

Verizon also blocks messages based on the urls they contain. Not sure about specific TLDs, but surely whole domains. Discovered this by running a service that sends a lot of messages through Twilio. Not sure if you would ever be notified of the block when sending from your phone.

In my opinion is not really to block spam, but instead to push message senders to buy the carrier's more expensive shortcode option.

[rsync]

... which can’t be reached from twilio, since twilio Numbers are not actual mobile numbers.

[zachrose]

What is it that can't be reached from Twilio? Carrier short codes?

[rsync]

Correct. Twilio does not give out any proper mobile phone numbers. Therefore you cannot send SMS from a twilio number to a short-code.