1. Find your Thunderbird profile folder.

  2. Click File ▸ Import.

  3. In the Importer Type tab, click Import a single file.

  4. Go to the folder in which Thunderbird stores its data. You will have to make sure to show hidden files in the file selector dialog.

    • If you would like to import Thunderbird mail, go to Mail/Local Folders (for local mail accounts) or ImapMail/servername (for remote mail accounts). servername will be the address of your remote mail server. Files without a file ending include your messages (not the .msf files).

    • If you would like to import Thunderbird/Lightning calendar data, you may be able to export your Thunderbird events as an .ical/.ics file first, and import these files into Evolution. This is required as Thunderbird stores its calendar data in a non-standard database format.

    The file type will be automatically determined.

  5. Choose the destination (e.g. the folder or calendar in Evolution) for the imported data.

  6. Repeat the import steps until you have imported all your data.