I have a website that serves dynamic eml / mbox files with a
content type of
message/rfc822. To open them in the MUA, I
have the MIME type associated:
$ xdg-mime query default message/rfc822 mutt-open-rfc822.desktop
It works flawlessly in Konqueror but not Firefox 56.0. Firefox
simply ignores the .desktop file. Instead, it offers to open the
link in the editor (associated with
Choosing the option “other” in the menu “Applications”, one can navigate to and select the appropriate .desktop file but the setting has no effect and the editor is restored next time the menu is opened.
Setting this to “always ask” offers an option to run xdg-open on it, but this loses the content-type and again, the editor is chosen.
How to coax Firefox into adhering to the XDG setup?