Which type of mail service is used for companies with large daily mail volumes?

The correct answer pertains to Caller Service, which is specifically designed to accommodate businesses with large daily mail volumes. This service allows companies to receive their mail in a more streamlined and efficient manner directly from the post office. It provides a dedicated mailbox so that businesses can manage their incoming mail more effectively, which is essential for organizations handling a significant volume of correspondence daily.

Businesses that utilize Caller Service can quickly pick up their mail rather than waiting for traditional mail delivery, thereby improving their operational efficiency. This is particularly beneficial for businesses that rely on timely communications and need to manage large quantities of mail regularly.

In contrast, while the other options like Priority Mail, Standard Mail, and Global Express Guaranteed may serve different purposes for various types of mail services, they do not focus specifically on the needs of companies with high mail volumes in the same manner as Caller Service does. Those services are more general and are not tailored for the unique requirements of businesses that generate a substantial amount of outgoing and incoming mail on a daily basis.