“Apple touts their network of nearly a billion devices capable of spotting AirTags, and if there are that many, it should be easy to track this envelope across the country.”
The AirTag pinged its location from the sorting office within half an hour of the mailbox pickup. Every postal worker’s iPhone became an unpaid tracking relay. That is great for finding a lost parcel. It works just as well for tracking a person who never agreed to carry one.