What is the primary focus of Zones 1-4 in mailing regulations?

The primary focus of Zones 1-4 in mailing regulations relates specifically to parcel size and weight categories. Understanding these zones is crucial for effective mailing practices, as they determine the various classifications and fees associated with shipping parcels based on their dimensions and weight.

Zones are used to classify how far a parcel must travel and the associated costs for that journey. Each zone corresponds to a specific distance from the point of origin to the destination. By organizing shipping based on parcel size and weight within these zones, postal services can efficiently manage logistics and pricing structures, ensuring that customers are charged appropriately for the services they require.

This focus helps businesses and individuals navigate mailing options more effectively, as they can assess their shipping needs based on the specific characteristics of their parcels. The other options, while related to mailing and shipping, do not encapsulate the primary purpose of these zones as accurately. For instance, international shipping rates pertain to cross-border logistics, domestic shipping classifications categorize mail within the country, and priority mail rates are specific to expedited services but do not address the foundational aspects of size and weight under the zones' framework.