I've been texting to two people for months. All of a sudden it stopped working -- Message "Not Delivered". I can send and receive texts from each individual but not to the group. No phone numbers have been changed. Any help would be appreciated.
It might have something to do with a problem with your or someone else's carrier. I only text to one person at a time, but sometimes my texts do not want to go through, especially if there is a photo attached.