Mailbox backup on mail server

Hi,

can anybody tell me how a server based backup of individual mailboxes (done by an administrator) and the related restore is supposed to be done? Server is 10.7.4 with no third party software.

BTW: if an Open Directory user account gets deleted accidently and a new account with the same name and UID, but a different OD identifier (which seems to be used by dovecot) is created: how do I transfer the mail between them (meaning there dovecot IMAP stores)?

Kind Regards

COWegner