Which of the following is NOT considered a Retail Communication Channel?

Mailing lists are categorized as marketing tools used to target specific consumers and do not function as direct channels for retail communication in a transactional sense. In contrast, self-service kiosks, automated teller machines, and contract postal units are designed explicitly for customer interaction and service transactions.

Self-service kiosks enable customers to conduct transactions independently, such as purchasing stamps or weighing packages, enhancing the accessibility of postal services. Automated teller machines facilitate real-time financial transactions, a vital aspect of postal service offerings. Lastly, contract postal units operate similarly to retail outlets, providing a range of postal and financial services in a physical location, thereby engaging customers directly. Thus, the other options illustrate clear retail communication channels, while mailing lists serve a different purpose in marketing and outreach strategy.