Hi James,
First, I want to apologize for the inconveniences and challenges you're facing. Over the last year, mobile carriers have made numerous changes that have impacted what types of SMS, and how SMS may be sent. This is unfortunately something that is impacting the entire industry.

One of the biggest impacts, as you are discovering is that business SMS is now being classified differently, and as such now operates under a new set of rules. By default, any messages containing any references to drugs that may be illegal are blocked by upstream providers/ the carriers. This means that we are unable to lift the restriction as it is not our restriction to lift.

You may be able to apply for a special exemption with the carriers through The Campaign Registry (TCR), but even paying the special exemption fees there are no guarantees that your application will be approved. Instead, I would recommend first making sure that all recipients you message have opted in to your SMS (SMS promotions cannot be sent unless you have explicit permission from the receiver to do so), and that your messages be generic in nature - ie "Have you been charged with criminal possession?..."

I'm sorry I cannot be more helpful here, but again this is a change impacting the entire industry.

If there's anything else I can do to help, please let me know.

- Mike

That was exactly my thought. Filtering words in text messages are done from carrier level and not from any system or product and done under the law of the country. I don't see RingCentral can do anything even they allow from their system as it will be getting block from carrier firewall which has to go through the guideline of the government.