My text messages are not deliverable

Are you referring to an iMessage or an actual SMS? SMS/MMS are controlled by your cellular carrier. You would need to speak to them. You can take a look at this support document for help. If you can't send or receive messages on your iPhone, iPad, or iPod touch - Apple Support

Are these SMS or iMessages that are not deliverable? Regardless are they not deliverable to any one or just specific individuals?