I would assume someone with rudimentary knowledge would know that, especially when it comes to government servers. You can't delete anything from the Internet. You can't make an email disappear once it's sent or received. You cannot do that. It is impossible. For anything I sent, there are backups of backups; there are backups of servers. With multiple servers being involved, each server has its own backup routine, and emails exist everywhere.
You cannot make an email disappear just because you deleted it from your laptop.