Comment 108 for bug 490935

It has been over six years since the last real discussion took place and almost two decades since the issue was created. Are there any objections from the Thunderbird team or hasn't there just been any volunteer to implement the feature?

I have another use-case for this feature: Many scanners nowadays can send emails with the scan attached. By default, though, these mails have a very generic subject. Being able to change the subject from the mail client conveniently allows finding particular scans later on.

I have been doing this in the past using the [Header Tools Lite](https://addons.thunderbird.net/de/thunderbird/addon/header-tools-lite/) addon. This addon, however, is not compatible with newer versions of Thunderbird. After looking through [Thunderbird's WebExtension APIs](https://thunderbird-webextensions.readthedocs.io/en/68/), it seems like editing an email's headers is no longer possible at all. It would be great if we could get at least an API to modify (or create new) mails.