I currently have an iPhone 5s.
When sending an iMessage (using wifi or 3G) the phone is supposed to convert the message to a SMS.
When sending a SMS to my wife's iPhone 5 (who has iMessage turned off), she doesn't receive the message. I either have to turn off iMessage or she has to turn it on.
It's the same with my mother who is using an iPhone 4s.
We are all on telecom, anyone have the same issue or know of a fix?