- Click Find under Configure Your Email File.
- Locate the file pertaining to the Mozilla Thunderbird folder you want to import into Gmail.
- You can find the files corresponding to your Mozilla Thunderbird folders under your Mozilla Thunderbird message store folder.
- You probably have to make Windows display hidden files and folders to see the Application Data folder.
- Use the files that do not have a file extension (not the .msf files).
- Click Open.


