cp msgFilterRules.dat /other/mail/folder
edit msgFilterRules.dat change all instances of your old mailbox: actionValue="mailbox://joes@mail.server.com/name"
to:
actionValue="imap://joes%40server.com@mail.server.com/INBOX"
sed s/'actionValue="mailbox:joes@mail.server.com'/imap://joes%40server.com@mail.server.com/g msgFilterRules.dat-........