When mailing, what must be clearly visible on the return address?

The return address on a piece of mail plays a crucial role in ensuring that undeliverable items can be returned to the sender. For the return address to be effective, it needs to include all components: the street address, city name, and ZIP code. Each part serves an important function in identifying the sender's location clearly.

The street address provides specific information about where the sender is located, helping postal services to pinpoint the right area. The city name is vital for sorting and identifying regions, especially in cases where multiple locations have similar street addresses. Lastly, the ZIP code is essential because it aids in efficient mail routing and delivery; without it, there could be confusion or delays in processing the return.

Having all these elements visible and clear on the return address ensures the highest chances of successful undelivered mail being returned to the sender, fulfilling the purpose of the return address effectively.