[Dovecot] problem migrating from maildir to dbox

Hello, we want to migrate Mail folders from Maildir to dbox without downtime. We change the mail_location to dbox in 10-mail.conf and restart dovecot. After that we use dsync -u user mirror maildir:~/Maildir. The problem is that if INBOX exists the dsync create a new folder with name like b5893c0a93ff694e551200002dfa3112 Can I migrate to the existing INBOX? or How can I merge the 2 INBOX folders? Thanks for your help! Regards,

-- Ramon