Occasionally, a message which I'm 100% certain was sent and was not previously flagged will randomly get flagged as unsent (triangle with exclamation point). I have resent them only to have them flagged again. My only recourse thus far is to delete the offending messages, but it's been happening from time to time.
jpietros, we understand how important it is to stay in contact with others, whether it be messaging or any other process. We want to help in any way possible. Does this happen with just one contact in particular? Do you have problems with calls or accessing cellular data as well?