This is because Fraud Guard has identified potential fraudulent messages being sent to one or more destination. A temporary block on SMS traffic has been placed for the next 12 hours on the prefix you used. This block will be lifted at the end of this 12-hour period. If further fraudulent activity is detected after this block, this pattern will continue with further temporary 12 hour blocks until the issue is no longer observed.
We identified SMS fraud occurring within your Verify product.
You do not need to take any specific action. The block is temporary and will resolve in 12 hours if we do not detect additional fraud.