Which of the following tools provides access to postal manuals?

The correct answer is Postal Explorer because it is specifically designed to provide users with access to postal manuals and related information regarding postal regulations and services. Postal Explorer serves as an essential online resource for postal employees and others who need to reference the vast array of postal documentation, including rate charts and other regulatory information.

While the other options may contain valuable information relevant to postal services, they do not focus solely on providing access to postal manuals. For instance, POM (Postal Operations Manual) offers operational guidance but is a more specific document rather than a comprehensive access point for various postal manuals. Policy Net relates to postal policies and may not directly reference manuals, and the Forms Page primarily provides access to postal forms but does not contain the broad scope of postal manuals that Postal Explorer offers. Thus, Postal Explorer stands out as the most effective tool for this particular need.