[Dovecot] disable lazy_expunge for some mailboxes?

[Frank Cusack]

How to disable lazy_expunge for certain mailboxes?

My problem is I have a public namespace, whose mail is on a different
filesystem than user mails.  Some users are allowed to expunge on this
shared mailbox, but lazy_expunge is stopping that from working since
the mail has to cross a filesystem boundary to make it into the
lazy_expunge namespace (location is under the user's home directory).

As a workaround can I run a daily cron job to remove messages with
the \Deleted flag on them?  If so how do I find them?

thanks
-frank