Hello Robert,
[... snip ...]
of course I'm totally with you: asking other people for help, is often
a good - if even not the only way to getting things done. It was not
my intention to insult you! I hope this did not come in to your mind ...
Personally I would have a look at the mentioned Dovecot-backup-script
as a start. It does really a very good job! Cudos to Klaus Tachtler!
Another option could be, to sync your mail via mbsync/isync or
offlineimap to your Notebook ... but as an alternative backup, it
depends on how many users are on your Dovecot-server.
In a second cycle, you can then extend or modify this script - as I
have been doing.
But you should bear in mind, that you should have at least 2-3
replicas of your data on different storage, for having a good backup.
Cheers Christoph.
-- Christoph Haas