What type of mail class is typically used for sending letters and postcards?

First-Class Mail is the appropriate mail class for sending letters and postcards because it is specifically designed for personal and business correspondence. This service ensures timely delivery, typically within one to three business days, depending on the distance. First-Class Mail is the fastest and most affordable option for sending lightweight items like letters, postcards, and small parcels up to 13 ounces.

In contrast, Priority Mail is a faster shipping option that is generally used for packages and items that need expedited delivery, and it includes features like tracking and insurance. USPS Standard Post is typically used for larger parcels and is not meant for letters or postcards. Media Mail is a specialized service for shipping educational materials and media, such as books, and it comes with specific restrictions regarding the type of contents that are permissible.