How to transfer Maildir files in Thunderbird MBOX format without any problem? Download and open Maildir to Thunderbird Tool that knows about the complete solution to convert Maildir files in Thunderbird MBOX format so that you can import it into Thunderbird application. With this program, you can move bundles of Maildir files to Thunderbird including all attachments and other details. Additionally, performer can take its all advance benefits as like- preview of emails, save report, preserves email details, etc. All Windows versions are suitable for this program.