Which of the following is true regarding service of process?

Service of process is a critical component of civil procedure, as it ensures that a party is formally notified of legal actions against them. The requirement for proof of delivery to be filed with the court is essential because it serves to establish that the defendant has been adequately informed of the lawsuit and has the opportunity to respond. This proof can generally take the form of an affidavit or certificate of service, which provides the court with a record that service was completed according to the rules.

This is significant because without proper proof of service, a court may not have jurisdiction over the defendant, which could lead to challenges regarding the validity of any judgments obtained. Filing this proof acts as evidence that the rules of service have been followed, maintaining the integrity of the judicial process.

In contrast, the other options do not align with the procedural requirements of service of process. For instance, using fax or email for service is generally not permissible for initiating litigation, especially without formal notice. Documentation proving the recipient's awareness of the contents isn’t a requirement of service, as mere delivery suffices. Lastly, while paralegals or legal assistants may perform service under supervision, it is not limited solely to them; attorneys or any authorized individuals may also effectuate service.