What postal classification includes mail like magazines sent regularly?

The classification that covers mail such as magazines sent regularly is Periodicals. This classification is specifically designed for publications that are issued at regular intervals, such as weekly, monthly, or quarterly. Periodicals enjoy certain postal rates that make them cost-effective for both publishers and subscribers, which is beneficial for maintaining a consistent circulation.

While Standard Mail could be considered for various forms of advertising and promotional mail, it does not specifically cater to regularly published materials like magazines. Parcel Post is intended for packages and parcels, and Priority Mail is used for expedited service, which does not typically apply to regular magazine distributions. Hence, Periodicals is indeed the correct classification for regular mailings of magazines.