Recently my mother's doro phone has an issue. The phone can received texts but when she sends a text the phone said it has been sent but it never arrived. She has a unlimited text plan. I checked the SMS Centre number, seems correct and I put my SIM in her phone and it's working. So I bought another Doro phone for her but the new one has the same problem. Do you think it could be the SIM itself?
Any ideas will be very helpful, thanks.
