Which of the following should mail orderlies avoid when delivering mail?

Delivering to an unauthorized individual is crucial to avoid because it directly relates to maintaining the security and confidentiality of the mail. Mail orderlies must ensure that mail is only delivered to designated recipients or authorized personnel to prevent sensitive information from being disclosed to individuals who are not entitled to receive it. This practice not only protects the privacy of the recipients but also upholds legal and organizational guidelines regarding the handling of mail. Safeguarding the mail delivery process helps prevent issues related to identity theft or misdelivery of important documents.

While the other options involve factors that can impact efficiency or timing, such as the type of mail being delivered or delays, they do not carry the same level of importance regarding security protocol as ensuring that mail reaches the proper individual.