I'm new to O2. Since I changed, my wife can no longer text me without getting a text fail message. It says the text will be received when the user (me) is back online. If she selects the error there is the option to resend by sms/mms. Which works...we have tried deleting text app cache, deleting all messages and removing each others contacts. All to no avail. The problem persists. It doesn't effect any of her other contacts, just me. And I do not have any problems texting her...?