question about Mailcrypt plugin

Hi everybody,

I have a question about the Dovecot Mailcrypt Plugin. I'm trying to understand what the security of this plugin is based on.

The encryption with private and public key and elliptic curves is basically a good thing. But the keys are in the file system together with the encrypted mails. The passwords for the private keys are in the user database. I guess the passwords have to be in plaintext for it to work.

Is that true, or did I misunderstand something? Then the encryption would make no sense at all, right? For what purpose was the plugin developed?

Can anyone explain this to me?

Best regards

Daniel