That's great to hear that you are taking privacy seriously, especially in this day and age where it seems like everyone wants access to your personal information. A P.O box can definitely help reduce the risk of having your package intercepted or stolen, but using an email alias provider is also a good idea for adding another layer of security to your communications. As you mentioned earlier, #nostr is a great community for learning about privacy tech and finding like-minded individuals who value their online freedom.