Importing mailboxes from other Mail.app installation
I reinstalled Mac OS X on my powerbook again, just to get that fresh feeling that a newly installed OS gives you. Anyway, I thought it would be helpful to know if you do this, that since Mail.app lacks the possibility to import mailboxes from another or previous installation of Mail.app (this comes in Jaguar), you can import it easily yourself. It’s best to do this before running Mail.app the first time!
You probably backed-up your home directory, or at least the Library directory. Copy the Mail directory from your backup into /Library/. Then copy the file com.apple.mail.plist from your backup into /Library/Preferences. Then launch Mail.app, and everything looks like before!