To import EML files to Thunderbird, you can use drag & drop method. Create a new folder in Thunderbird and drag & drop EML files in this newly created folder but it is not suitable if you large number of EML files. Using ImportExportTools, you can also import EML files to Thunderbird. However, with Advik EML Converter, you can upload EML to Thunderbird in a few simple clicks. The software can directly import EML to Thunderbird without any external help. It can upload multiple EML files at once. It is a trustworthy solution that does not lose any single bit of data during the process.