Hello.
For the past few weeks I have been noticing that various emails were bouncing when sending to sms.myboostmobile.com, which has been a reliable SMS gateway for 10+ years. I contacted "Advanced Support" on Saturday who said that Boost Mobile has discontinued their SMS Email Gateway after the DISH merger. Just a heads up if you have any SMS email gateways being used that you should also periodically test them, to ensure they are still active.
Matthew