On Thunderbird there’s an option to Copy message link, which outputs a link that starts with mid:, but I can’t actually use an app to ‘click so it opens’, I have to use xdg-open: any ideas how I can get this to work on say Chromium? I feel like the whole point of links is to be a click away from the content!
The issue is not really Thunderbird itself. The root problem is that “mid:” is a niche URI scheme and Chromium handles custom protocols inconsistently on Linux, especially when the protocol is delegated through “xdg-open”.
mid: is a valid URI scheme for Message-ID references in email systems, but browser support is extremely limited. Thunderbird can generate those URIs, and the fact that xdg-open mid:... works already proves your desktop environment is resolving the scheme correctly. That strongly suggests Chromium is the actual weak point here, not Thunderbird.
Firefox generally delegates unknown schemes to the desktop handler properly, while Chromium often treats them as plain text, a search query, or blocks them unless the protocol is explicitly trusted or internally registered.
You can try explicitly registering the scheme in your MIME associations:
x-scheme-handler/mid=thunderbird.desktop
then rebuild the desktop database:
update-desktop-database ~/.local/share/applications
and test again with:
xdg-open 'mid:<message-id>'
But even with that, Chromium may still refuse to dispatch the URI correctly. Chromium’s external protocol handling on Linux has had longstanding inconsistencies with custom schemes.
At that point, the realistic options are:
- use Firefox for
mid:links, - use a small intermediary helper script that calls
xdg-open, - or use a Thunderbird extension designed around reopening messages via Message-ID instead of relying on browser protocol dispatch.
So your intuition is completely reasonable. A “copy message link” feature implies clickability, but the ecosystem support for mid: URIs is surprisingly incomplete, especially in Chromium-based browsers on Linux.