How do I move saved Mail.app mail from one machine to another?

I have two OS X machines running Snow Leopard, a laptop and a desktop. I have saved mail messages on my laptop that I'd like to move to my desktop. However, the obvious method—copying ~/Library/Mail/Mailboxes/Saved Items/ and …Saved Items.mbox to ~/Library/Mail/Mailboxes—doesn't work right. After I did this, I can see the folders on the left side of Mail.app, but none of the messages show up at all in the message list at the top of Mail.

Funny thing is, I can see these messages just fine if I enter relevant search terms into Spotlight.

What's the minimum amount of files that I need to copy from my laptop to my desktop if I want these e-mails to show up in Mail.app? I'd rather avoid obliterating copying over other settings if at all possible.

For backing up Mail, and your mail configuration, the simplest thing is:

1. Copy ~/Library/Mail to the new computer, and place it in the same location
2. Copy ~/Library/Preferences/com.apple.mail.plist to the new computer, and place it in the same location
3. Start Mail.app

If you just want to backup a particular mail folder, just right click on the mailbox, and choose "Archive Mailbox". Choose a destination, and probably you'll want to click on "Archive Subfolders".

You could try selecting the new (empty) Saved Items mailbox and do Mailbox > Rebuild