Config Editor
Exporting Mail in Mbox Format
Handling Receipt of Duplicate Emails

Thunderbird Tips

Config Editor

Go to Settings, scroll to the bottom and click the Config Editor… button.

Exporting Mail in Mbox Format

https://github.com/thunderbird/import-export-tools-ng

Handling Receipt of Duplicate Emails

Use the config editor to modify the value of mail.server.default.dup_action.

keep = 0
delete = 1
move to trash = 2
mark as read = 3

https://superuser.com/questions/158996/removing-duplicate-emails-in-thunderbird

-- Frank Dean - 07 Sep 2025

Related Topics: FirefoxTips