Sending a short message with the same information shows that one of the mobile phone numbers failed to be sent. How to delete it?

Click Unsent SMS, click Settings in the upper right corner, and then click Delete.

There are many reasons why the SMS was not sent, such as the arrears of the mobile phone, the arrears of the other party's mobile phone, or being blacked out by the other party.

"There are two kinds of short messages: one is text or digital information directly sent or received by users through mobile phones or other telecommunication terminals. The number of characters that users can receive and send short messages at a time is 160 English or numeric characters or 70 Chinese characters.