Ok, I'm going to consolidate how to do this in a bunch of easy steps:
- Download Thunderbird 2
- Download Mozilla Mdimporter
- Get Thunderbird all set up how you want it
- Unpack the Mozilla Mdimporter and leave the uncompressed file on your desktop where it's easy to find
- Press F11 to clear your screen so that you can see your desktop
- Double-click your hard drive icon
- Click "Library" (I'm assuming you're in column view here, so if you're not, you should probably just switch to it)
- Click "Spotlight"
- Drag the Mozilla Mdimporter file (probably named "Thunderbird" with no extension) into the Spotlight folder
- Close the Finder window
- Hit F11 again to restore everything
- Open Thunderbird
- Go to the "Thunderbird" menu
- Select "Preferences"
- Click the "Advanced" icon
- Click the "General" tab
- Click the "Config editor" button next to "Advanced Configuration"
- Scroll down to "mail.spotlight.enable" -- click it and change it to "true"
- Shut down Thunderbird
- Restart your computer
- Launch Thunderbird
- If everything is working correctly, then you did everything correctly
- Give the computer 30 minutes to do some indexing and enter in some search terms from an e-mail into Spotlight -- you should see the results show up as "Mail"
As with all of these sorts of things that I post, your mileage may vary and I'm happy to help with an further questions.
Some sources that I pulled information from:
Link -- dennis.ca has a post on how to do this with more detail than mine
Link -- MacOSXHints has a thread about this and though it's about the Thunderbird 2 beta, I don't think that anything's really changed
Thunderbird image from Max Boss