Transfer of Old Mail Box to New Machine



I wonder if anyone can help me in telling me how i transfer my mail account from my old emac (OSX 10. 2.8) to a new emac running OSX 10.4. The new emac has the new mail program and i want to transfer all of my old settings + all of my emails.
You can put the newer keychain in place of the old keychain. You
need to rename or move the old one to do this to save the old one. Once the
new keychain file is in place log out and back in.