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 ...

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 ...