For messages that have already been sent, long pressing the message shows an option to remove the message. But for message that are being sent, especially on a slow Internet connection, there is no way to remove the message or stop it from being sent.
For messages that have already been sent, long pressing the message shows an option to remove the message. But for message that are being sent, especially on a slow Internet connection, there is no way to remove the message or stop it from being sent.