[Dovecot] Auto-subscribe to folders

[Juan Asensio Sánchez]

Hi

I will use autocreate plugin in a new installation, and client has
asked me if the users can be auto-subscribed to certain folders.
Example: the users will have an autocreated Junk folder (for SPAM) and
we want the users not to be un-subscribed for this folder; so if the
user wants to be unsubscribed (from outlook, webmail, etc), there are
two options: a) the action is rejected or denied; b) the next time
he/she logins, then the folder is autosubscribed again. Could this be
done? How?

Thanks in advance.