I have need to archive mails. Is there possibility to configure master user/password for access to all mail users accounts ?
There is no master password. You can e.g. do mail archiving with the auto bcc function from postfix and send a copy of each incoming and outgoing email to a archive mailbox.
Till I know that. What to do with current users email boxes ? I have boxes which is 10GB or more and contain mails 7-8 years old. I wan't to archive them without know users password. Is there any way to do that ?