So when I tried this way I got the following output:

user'@'host:~$

doveadm -o plugin/mail_crypt_private_password=desired_password mailbox > cryptokey generate -u user -UR

user'@'host:~$

And when I tried this way I got the following output:

user'@'host:~$doveadm -o plugin/mail_crypt_private_password=desired_password mailbox cryptokey generate -u user -UR Folder Public ID user'@'host:~$

In both cases I sent a new email to the server, and I got errors stating the mailbox can't be opened

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