Cannot text to non-iPhone users on phone, iPad or Mac computer w/ AT&T plan and wifi
I can send messages to anyone who has an iPhone from any of my devices. My settings on my iPhone show "Send as SMS" and I have tried turning this setting on and off to make sure that's not the issue. I cannot send texts to my sister who uses a Samsung phone, not from any of my devices: computer, iPad, or iPhone. The AT&T carrier is the issue. How do I resolve this?