Migrating From Windows Live Mail or Vista Mail to Thunderbird 3 in XP, Vista or Windows 7

Thunderbird will migrate your email from Outlook or Outlook Express using the Import tool in the Tools menu.

Thunderbird does not have an import to migrate from Windows Live Mail or Vista Mail to Thunderbird, like it does for Outlook or Outlook Express.  So we kind of have to do a little navigation around the problem.  Hopefully in the future Mozilla will include an import for Vista Mail and Windows Live Mail for Thunderbird.

Migrating Email Accounts, Filters & Settings:
Sorry, no information on that as of yet, if possible at all.  If someone knows how to do it, please post in the comment section.  Thank you.

Migrating Messages:
Windows Live Mail stores its messages in the .eml format. You can import these message files with:  Thunderbird ImportExportTools extension.
https://nic-nac-project.org/~kaosmos/mboximport-en.html

1. Go into Windows Live Mail and at the top menu click “File/Export” and select Messages.
2. Choose the Windows Live Mail format and click next
3. Choose a location for the backup, (make a folder on your desktop), and click next.
4. Select the message folders you want to backup and click next.
5. Download the ImportExporttools extension (above) and add it to Thunderbird by going into the “Tools/Add Ons” section or following the directions on the site if you don’t know how to install extensions.
6. Restart Thunderbird.
7. Click “Tools/ImportExportTools/Import all eml files from a directory/also from its sub directories”, and browse to the messages backup folder you just put on your desktop in the steps above and select it.  Click Ok
8. Wait as the messages are imported.  All done.

Migrating the Address Book:
http://forums.mozillazine.org/viewtopic.php?f=28&t=1576435

Detailed instructions can be found here : http://www.bakoweb.com/bakoblog/2010/migrating-windows-live-mail-or-vista-mail-address-book-to-thunderbird-3-in-windows-xp-vista-and-7/671/

1. To import the address data, export the address data in Win Mail to a CSV format file.
2. Next, manually create at least one record in the Personal Address Book in Thunderbird, then export the data from that address book.
3. Click on the name of the new address book, then use menu path Tools->Export->Address Books->give the output a name and select “save as type” Comma Separated (CSV).
4. Load the exported file into Excel (or some other spreadsheet program) and do the same with the data file from which you previously exported from Win Mail. If necessary, reorder the columns in the file from which you intend to import so that it matches the order of those in the export from Thunderbird.
5. Save the data back to CSV format and import that to Thunderbird.
6. Open a contact record from the newly created address book in Thunderbird to confirm that the email address field is properly populated. If it is, you can delete the address book created by the first import attempt and delete the records from the Personal Address Book.
7. Finally, move or copy the data from the latest import to the Personal Address Book.