UPDATE: Twilio now offers Two-Factor Authentication. Great to see!
Today I learned (TIL): When using Twilio to send SMS text messages, messages with urls shortened by goog.gl link shortener will get blocked. In Twilio, it appears that the SMS text message completed successfully; however, the mobile phone never gets the message. Since Twilio does not know that the message is getting blocked, you still get charged on their end.

I assume that the same ‘lack of error message’ problem would exist on other with other SMS gateways and I do not fault Twilio. (I have been extremely please with their VoIP service).

In general, I would recommend staying away from all 3rd party url shorteners if you are building an application that would share any link from the web and try to sniff out other shortened linked. If you control the shortner and your domain gets added to this arbitrary blacklist, you have all the data so you can duplicate the shortening someplace else that is not blocked and abandon the blacklisted shortener. It is very hard to explain to the problem to every end user who is using your “Share My Widget to Text” application that they must prescreen all links before the system will work.

I am toying around with something that sends pre-recorded messages via http link in a text hours later so I have an easy work around for long urls provided by Twilio (I can just move the file to my domain) but I can see where this could be a pain for future projects. If you know of any url shorteners that do work 100% of the time, please let me know. I would be interested to see how they keep on the whitelist.

The “something” is a “ reminder text when you have been drinking“. Feel free to give it a test – it is super basic but gets the job done.

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