Credit: iOS 13 Concept / Michael Calcada

While Apple didn’t detail the feature during its WWDC keynote, there’s no doubt that it’ll be much appreciated by users plagued by spoofed and spam calls. It’s called “silence unknown callers” — and it basically does just that.

According to Apple’s iOS 13 webpage, the feature uses Siri intelligence to allow calls from phone numbers in Contacts, Mail and Messages. Any other calls will be automatically sent to voicemail without ringing or buzzing your device. That includes numbers that have been spoofed to seem like they originated locally.

The feature will offer a useful middle ground between receiving all unknown calls and turning on Airplane Mode or Do Not Disturb.

Presumably, the Siri intelligence aspect of it will allow calls that appear in emails or text messages, even if they aren’t in a user’s contacts list. And, if a call from an unknown number is actually important, the caller will always be able to leave a voicemail.

That will go a long way toward reducing the annoyance of spam calls. Most carriers are in the process of implementing some type of call authentication system. But these systems won’t block unknown callers — they’ll only verify whether a call is being spoofed. In other words, the calls will still ring your device and disturb you.

Apple’s system does away with that problem. And while there are some currently available third-party apps that have similar functionality, the silence unknown caller feature is baked right into iOS 13.

The feature won’t be automatic — users will need to enable it explicitly. And, of course, the feature certainly won’t be for everyone.

iPhone business users, for example, will be inadvertently sending new customers, clients or colleagues to voicemail. That’s not great. But the average user who doesn’t need to keep their phones open to unknown callers may just find the system invaluable.

There is currently no perfect solution to stopping spam and robocalls. And while spam and robocalls are a worsening problem, there probably won’t be any one foolproof defense against them anytime soon. But Apple’s new silence unknown callers feature will be a useful addition to any user’s anti-robocall “toolkit.”

The silence unknown callers feature will launch in the fall when iOS 13 becomes available to the public. If you’d like to end robocalls now, try this useful app.