If you think the package might be lost in transit (it’s taking too long to arrive), you can always avail yourself of the tracking services provided by UPS, FedEx, and other major carriers. These services typically provide tracking numbers for all packages shipped. In most cases, you can track your package by entering the package’s tracking number into the carrier’s website.
The one major shipping service that doesn’t offer tracking (by default) is the U.S. Postal Service. What you can get from the postal service (at a cost of from $0.45 to $0.55) is delivery confirmation. USPS confirmation, however, does not confirm that an actual person received the package; it confirms only that the mail carrier delivered it. (Stuck it in the mailbox, that is.)
If you want a signature confirmation on a USPS shipment, you need to send your item with either Signature Confirmation or the certified mail option. Signature Confirmation costs $1.80, while certified mail costs $2.30. Both require the recipient to sign on delivery, and are good options if you’re shipping something extremely valuable.