Problem: Can't send SMS and also cannot activate iMessage
After exchanging my iPhone 4 for a iPhone 5S (and getting new nano-SIM), SMS wasn't working!
After a lot of googling I decided to just check the settings.
- Go to "Settings", choose "Phone"…
- There, choose "Telekom.de Services"…
- There, check the "Status Messaging"…
- yes, this should have been obvious…