due to legal reasons, we should be able to backup/restore every single mail.
If possible, those mails should be restoreable/viewable without the mail-application itself.

Therefore there should be a "path" to the mails in order that an external backup-application can access/save the mails.

If the meta data header of the mail would be stored together with the message file, that would be a pretty easy task, but as far as I know,
Zimbra does store the meta data in a db.

Any tips - I am pretty sure there are better approaches available - are appreciated very much. Thank you!