I have a Samsung J3. For the last week or so I have been able to receive but not send SMS.
When I try to send a message I get the error message 'Message failed to send
I have tried/checked:
Sending a message to myself - still fails
Checked the message centre number- it's correct
Restarted the phone
Factory reset of handset
I don't have another device that's unlocked or on ID so I can't test the SIM in another phone.
I can receive messages fine and make and receive calls.
I'd be really grateful for any advice on other things to try.