“My personal emails are my personal business, right?,”
No dear, not after CLASSIFIED material is found on your server!
You have forfeit all rights to privacy and your server is confiscated and the investigators will determine which items are of interest.
Once they are done with the investigation and that means all prosecutions are complete, the server will be destroyed.
“My personal emails are my personal business, right?,”
Tell that to the people the IRS targeted for political reasons.