How to apply procmail to a maildir Mail/inbox?

[Mitchell Laks <mlaks@post.harvard.edu>]

Hi,

My main inbox has a bunch of mails that really belong in other mail directories.
They went to Mail/inbox because of an error in my .procmailrc

I have now fixed my .procmailrc to correct the errors
and now want to reapply the procmail to the contents of ~/Mail/inbox.

Thus, I would like to take all the mail in the inbox
and apply procmail and have the correct mail stay there
and those mails that belong in other directories be moved to them.

this is a 'feature' with kmail filters. 
I am sure I can do it with procmail too. 
I just want to do it carefully and not mess up my mail!

I have read about formail splitting with mbox format.

Here the mail I am working on already lives in Mail/inbox.
I dont want to end up with duplicate mails in Mail/inbox, or deleting things by mistake :).

Thanks,
Mitchel