Why can the mobile phone send text messages for a while and not send them out for a while?

Sometimes text messages can be sent out, sometimes they can't. There are several reasons: 1, the signal in your environment is poor, so it is recommended to send it in an open place with strong signal; 2. There are too many spam messages on your mobile phone, so it is recommended to delete some useless files; 3. There is an error in the information center. It is recommended to view it online on official website!