Which of the following specialty services provided by the USPS provides a proof of mailing at the time of mailing and the date and time of delivery or attempted delivery?

The correct answer is the Certified service provided by the USPS. This service offers proof of mailing at the time of sending, which includes a receipt that serves as verification of the mailing. Additionally, certified mail includes tracking options that allow senders to confirm the date and time of delivery, or if delivery was attempted. This feature is particularly valuable for important documents or communications where confirmation of receipt is necessary.

While Registered service also offers enhanced security and tracking, it does not specifically provide a proof of mailing at the time of mailing in the same straightforward manner as Certified. USPS Tracking is a tracking service that provides updates but does not confirm the act of mailing itself. The Certificate of Mailing service ensures that something was mailed but does not offer tracking or confirm delivery, making Certified the only option that meets all of the criteria laid out in the question.