Are those system messages saying "unsubscribe back to T" useful?

Generally speaking, it is not possible. "unsubscribe back to t" is just a form, which has no practical effect.

Domestic communication operators can indeed unsubscribe from short messages if users reply and customers call to confirm.

However, under normal circumstances, if citizens reply to "T" for many times to unsubscribe, the SMS function will be affected, and finally they may never receive the push again. In the final analysis, "this is just a complaint about the SMS channel, but it will not be unsubscribed. Send it to users in the background, and users can still receive it.

Experts said: replying to "t" may reveal information, so it is recommended not to reply, otherwise it will be blacklisted.

Promotional short messages sent in the form of trombone involve merchants, short message agent platforms and short message recipients (namely users). Merchants entrust the SMS forwarding platform to send short messages with marketing content to users, and the specific unsubscribe method is determined by the SMS forwarding platform.

There are generally two situations: one is a technical problem, and the platform does not respond in time after receiving the unsubscribe signal; Second, the platform has not written the corresponding unsubscribe program, and the unsubscribe method provided in the SMS is only a gesture, which cannot play a practical role.