With the new version of iOS, it is possible to automatically direct calls from unknown numbers to their voicemail.
It is not always pleasant to receive calls from strangers, whether it is a person who has made the wrong telephone number, telephone salespeople or relatives who are making a bad joke of you. Fortunately, with iOS 13, it's possible to no longer be disturbed thanks to a new option.
This allows you to automatically send calls from unknown numbers to your voicemail. Thus, you are neither disturbed by the call nor obliged to answer or hang up to get rid of it. You will be able to read the voicemail message - if the person left one - at the end of their call, just as if you had missed their call.
To do this, nothing simpler. Go to your iPhone settings, Phone tab and check the option "Silent calls from strangers".
Obviously, your phone will always alert you to a call from one of your contacts, from a number you recently called, and from a number linked to a suggestion that Siri has access to.
In fact, if a message or an email contains a telephone number, it will be able to contact you despite the fact that it is an "unknown" number. A very useful exception if it is a professional or other number.
Remember to deactivate the option if you are waiting for an important call from an unknown number, a delivery man for example, it would be a shame to miss it.