Q: Why won't it let me send a iMessage it says not delievered

Hey Ajst9800,

Welcome to Apple Support Communities. 

It sounds like you're seeing a red exclamation point with an alert under it that says Not Delivered in the Messages app on your iPhone. Try taking a look at the article linked below which provides information and troubleshooting tips that should help you resolve this issue. 

If you can't send or receive messages on your iPhone, iPad, or iPod touch - Apple Support

Take care.