[Dovecot] importing plain mboxes to dovecot maildirs

[Radim Kolar]

> dsync(admin): Error: Failed to sync mailbox sent-mail-feb-2012: Mailbox GUIDs are not permanent without index files
> Well, you can work around if by letting it create indexes. Hm. Why exactly can't it create indexes? Do you have some setting disabling them?
indexes never existed because these mboxes were never used by dovecot, 
its not conversion from one format to another, its import.

Maybe open bug to add feature "dsync import" which will not depend on 
existing indexes?