How to remove sensitivity:private flag from all email message inmailbox

[chrisloup2]

How can i strip the sensitivity flag from existing emails in my
message journal?

basically if I'm on my user account, I cannot see email marked private
that is on the journal account, so its hard to port them to pst or
organise them.

I've already written a message sink to do the job for new emails, but
how do I do so for existing ones in the inbox?

thanks
Christopher