There are a couple of ways to do this.
One is via cyradm:
cyradm --user cyrus --server localhost cm user.dfrey.Sent
Then copy the mails themselves into the directory and run
reconstruct -r user.dfrey.Sent
I did what you said. Everything ran without error, but when I tried to open the folder with an e-mail client, it was empty.
Any other ideas? Thanks for your help. I really want to get my Sent e-mail back.
David Frey