How to pick up letters in zimbra?

Question

Zimbra

Good day.
Situation:
There is a user mailbox whose folder with letters was copied via ftp.
After the user took down all the letters in the box, the letters were uploaded back via ftp (although they should not be deleted from the server).
Zimbra doesn't want to see these emails because the entries were most likely deleted from the database.
How to explain to the Zimbra that there are letters in the folders? Because the letters are not displayed in the client.