The official Help documentation at mozilla.org describes procedures for Thunderbird and for Firefox whereby you can move your profile to another location and then simply point Thunderbird or Firefox to it through a simple edit of the "profiles.ini" file. This is much easier than Method 2, below, which requires more complex file editing. Some users have reported that the procedure sometimes does not work, however, and the failure may be caused by installed extensions and/or themes. [1] If you try this method and it doesn't work for you, see the Troubleshooting section below or try Method 2.

Initial testing seems to suggest that you can use this method to manually migrate a Mozilla Suite or Netscape 7 profile to Thunderbird, including all mail and account settings, but it may not work perfectly. To do so:

1. Copy the entire contents of the Mozilla Suite/Netscape profile folder (ending in ".slt"), including all subfolders, to your desired location.
2. Follow the procedure described here to edit your Thunderbird profiles.ini file accordingly.
3. Shut down Thunderbird completely (File > Exit).
4. Move the profile folder to the desired location. For example, on Windows, move the profile from C:\Documents and Settings\[username]\Application Data\Thunderbird\Profiles\xxxxxxxx.default to D:\Stuff\MyMailProfile. If you are reading these instructions because you want to restore a previously backed up profile, this step isn't necessary. Just note the current location of the profile you want to restore.
5. Open up profiles.ini in a text editor. The file is located in the application data folder for Thunderbird:
1. On Windows XP/2000, the path is %AppData%\Thunderbird\
2. On Windows 95/98/Me, the path is usually C:\WINDOWS\Application Data\Thunderbird\
6. In profiles.ini, locate the entry for the profile you've just moved. Change the Path= line to the new location.
7. Change IsRelative=1 to IsRelative=0.
8. Save profiles.ini and restart Thunderbird.
9. When you restart Thunderbird, go to "Tools -> Account Settings" and for each account (including Local Folders), click on "Server Settings" and verify that "Local directory" is pointed to the correct location. If it isn't, then click on the "Browse" button to fix it. You may need to exit and restart Thunderbird for these changes to take effect.

Open the Bookmarks menu and choose Manage Bookmarks. In your Bookmarks window, open the Tools menu, and choose Export.

In the "Export bookmark file" box, choose a destination folder for your "bookmarks.html" file. I suggest putting it in "My Documents". Click Save.