one-way synchronization

[Kamil Páral]

Hello,

how can I force offlineimap to do only a one-way synchronization? I want
to use it for backup purposes, that means download all emails from IMAP
server to local folders on the first run and update it (server->local)
on the next runs. But I *never* never want offlineimap to change
anything on the server, even when there is some involuntary change with
my local folders. I was looking for some "read-only" option, but I have
found none. I don't want to hope that there is no change with local
folders, I want to be sure it can't go wrong (at least from my side).
Can you give me an advice?

Thanks,
Kamil