What qualifies an article to be classified as 1st class mail?

First-Class Mail is primarily designed for personal correspondence, including letters and postcards, and one of its distinguishing features is weight and content limitations. An article qualifies as First-Class Mail when it weighs less than 13 ounces and includes personal correspondence or postcards. This classification allows for expedited delivery and is often chosen for items that need to reach recipients quickly.

While other categories of mail exist, First-Class Mail is specifically tailored for non-commercial items such as letters and postcards, which is reflected in the correct information regarding weight limits. In contrast to other mail classifications, items in First-Class Mail can also include various forms of personal correspondence, making this option particularly relevant for this question. Other options suggest weight limits and types of articles that do not align with the regulations governing First-Class Mail.