Sometimes Mail can get so tweaked, hacked, extended or just plain busted that reinstalling the whole thing from scratch is the only solution.

It happened to me once about a year ago. Last week Hawk Wings reader Fred emailed me asking how to do it.

First, you need to remove Mail from your system. Quit Mail. In Finder, drag your ~/Library/Mail folder to the Desktop. This gives you a backup in the event of something going horribly wrong and an archive of your messages, especially important if you use POP for your accounts.

If you use IMAP, your emails are all safely stored on the server and Mail will simply download them again, rebuilding its local cache, when you open the restored app for the first time.

Then do the same with your Mail preferences file, com.apple.mail.plist which you can find in the ~/Library/Preferences folder. This contains all your account information, which you should have written down somewhere as you will need to re-enter it.

For a complete uninstall, you will want to remove the contents of the ~/Library/Mail Downloads folder as well.

If you are using Tiger (10.4.x), reinstalling is simple. You can now reinstall individual apps from the installation disks, without the need for a third-party package extractor like Pacifist . Insert your installation disks and follow the instructions in this Apple technote, “Custom installs in Mac OS X 10.4″ .

This custom reinstall option can also be used with Address Book, iCal, iChat, iTunes and Safari.

If you are still using Panther (10.3.x), you will need to use Pacifist. It’s shareware (USD 20) and is fully documented online in English and French.

If you use IMAP, all you need to do now is open up your brand-new copy of Mail, enter your account details and watch as your messages are retrieved again from the server.

If you use POP, you may also want to restore your messages using the method outlined in an earlier Hawk Wings post.

Lastly, you need to install the 10.4.7 Combo update (PPC or Intel ), even if you have installed it before. This will update Mail.app to the current version.

Obviously you will need to reinstall all the plugins that you use. You may know what they are or you can find them again through the Hawk Wings Plugin and Addon List.