>[оверквотинг удален]
>>Попробовал у себя, переименовать не удалось :(
>>Вот такая ошибка у меня:
>>rename user.test user.test1
>>renamemailbox: Operation is not supported on mailbox
>>
>>возможно поможет пернос ящика: xfermailbox
>
>Не заработало, аналогичная ошибка:   Operation is not supported on mailbox
>
>Тогда нужно использовать утилиту типа imapsync.

http://www.oreilly.de/catalog/mimap/chapter/ch09.html
Top-level mailboxes cannot be renamed because of a Cyrus architectural issue. Renaming a top-level mailbox requires changes in other parts of the system, such as the mailboxes file, the quota subsystem, the mailbox subscription database, and the names of all mailboxes below the top level in the hierarchy. This can be a problem--many sites allow users to change their account names at some time after the account is initially created. It is also important to note that renamemailbox does not hierarchically rename mailboxes--it only renames the mailbox that it is given as an argument. All other mailboxes below that mailbox in the hierarchy are left untouched. CMU will provide a hierarchical renamemailbox command in Cyrus 2.0, but it does not yet appear in any release up through Version 1.6.22. Until cyradm supports hierarchical renaming, it will be of limited use on its own. Fortunately, as with many limitations, there is a usually a workaround. The workaround, which is implemented as a Tcl script in Example 9-2 in the next section of this chapter