A Thunderbird extension that automatically tidies up outdated external tags like [EXT], [Extern], and repetitive prefixes like Re and Fwd. Lightweight. User-configurable.
e.g., Fwd: Re: [EXT] Aw: [Extern] Re: [External]
In Thunderbird, go to Settings (the gear icon on bottom left), Add-ons and themes, and search TidySubject in Find more add-ons. Alternatively, install directly from here.
This project is licensed under the GNU General Public License v3.0. You are free to use, modify, and distribute this software under the terms of the GPLv3. Any derivative works must also be licensed under the same terms.
Pull requests and feedback are welcome! If you find a bug or want to suggest a new feature, feel free to open an issue.