How must proof of service by mail or national courier service be filed?

When proving service by mail or a national courier service, it is essential to follow the guidelines set forth in Rule 41(d). This rule outlines specific procedures that must be adhered to in order to ensure that the proof of service is valid and recognized by the court. These procedures may include requirements about documentation, the manner in which the service is executed, and how it should be filed with the court.

By referring to Rule 41(d), process servers can ensure that they are in compliance with the legal standards necessary for the service to be considered official. This is crucial, as the court relies on such filings to confirm that all parties involved have been properly notified, which is a fundamental aspect of due process.

The other options may describe practices that can be relevant in certain circumstances, but they do not specifically address the requirements set out in Rule 41(d). Therefore, adhering to this rule is vital for the lawful process of serving documents via mail or national courier service.