Which of the following is NOT included under official correspondence as per naval regulations?

Non-official emails are not included under official correspondence according to naval regulations. Official correspondence refers to communications that are created, received, and maintained as part of official duties and obligations. This typically encompasses written materials such as letters, memos, and reports that have formal significance within the naval framework.

Documents related to official business, as well as publications that provide guidelines or information pertinent to naval operations, also fall under the umbrella of official correspondence. Conversely, non-official emails do not have the requisite formality or adherence to regulations that characterize official correspondence. As such, they do not carry the same weight or implications as other forms designated specifically for official use.