This has been happening for a while now. Can't even text myself. Everything else on the phone works fine. Galaxy S3 updated to Jelly Bean. I've tried to restart, battery pull, shut off Wi-Fi, shut off Sync, text from native text app, reinstalled GO SMS, limited the number of texts per person.
Anyone else having same issue? Any suggestions other than a factory reset? Is there a backup running? Can I control the time of the backup?