If you want to remove duplicate emails from Mozilla Thunderbird then you can watch this video. This video has a step-by-step manual way to eliminate duplicate emails in the Thunderbird mailbox. On the other hand, you can try professional application to open Thunderbird mailbox on various other platforms.
Read more: https://www.mailsdaddy.com/blogs/solved-export-thunderbird-email-outlook-pst/
Read more: https://www.mailsdaddy.com/blogs/solved-export-thunderbird-email-outlook-pst/