Xiaomi NOTE can't send anything by SMS.

Hello, there are several reasons why the information cannot be sent out. You might as well know about it, refer to it and see if there is such a thing.

Reason one: the number sent. Whether the number sent is correct, whether there is 86 before the information, etc. Some systems can't recognize these.

Reason 2: Telephone charges. Can the phone bill guarantee the cost of sending messages (don't talk nonsense, I'm just listing the reasons)

Reason 3: SMS center code. Check whether the SMS center code has been changed.

Reason 4: Some software intercepts SMS operations.

Reason 5: The cell phone signal is not strong enough?

These are relatively common, because you said you were still posting them before, and that's probably all, so I won't list the others one by one.