When enabled, the opt-in Contact Key Verification gives automatic alerts if the iMessage key distribution services return device keys that have not been verified (e.g. if an unrecognized device has ...

When it works, iMessage is one of Apple’s best online services. With iOS 8 and OS X 10.10 Yosemite, it seamlessly merges SMS and instant messaging across all your Apple devices, and you won’t find ...