I'm using SpamAssassin to analyse existing emails, so I have an archive folder on my file system that contains a large amount of (already read, old) emails.
Among those emails there are quite a lot of spam emails that have not been analysed by SpamAssassin yet, because I only recently installed SpamAssassin on my system.
Is it possible to let SpamAssassin analyse the emails of that folder? I would like to filter out all the spam emails automatically.