Disable "open with" option on Firefox downloads (force Firefox to always save all files)

• Users open their web mail accounts, click on some attachment, and click "Open with Word".


• Users edit their precious documents for hours. Users save word doc and exit.


• Users can't find file.


• Users grab torches and pitchforks (last step optional).

The download dialog for Firefox shows two options: "Save file" and "Open with".

By choosing "open with", Firefox downloads the file to a temp folder and opens the associated application. I want to prevent this behavior.

I made my homework and searched the MozillaZine, and the Knowledge Base (like here, here or here) and if I understood correctly, the download dialog box will depend not on the file's extension, but rather on its mime type.

I know I can set the behavior by going to Preferences > Applications, like this:

However:

• Firefox relies on the mime type informed by the server. But it can be itself incorrect, omitted, or redundant (one file type can have multiple mime types, or vice-versa).


• Firefox remembers the "Do this automatically for files like this from now on" check-box on a per-mimetype basis. If I want to enforce a certain behavior, I have to manually set it for each mime type.


• I can not create new entries in the applications list. It is populated only when a new download is made from an unregistered mime type. Only then I can change the behavior in the list.


• I can edit the mimetypes.rdf file, forcing the "save file" behavior, but I couldn't find a way to enforce this to all files.

What I need is a way to (preferably) make it impossible to open with an external application, or at least to force the file to be saved.

I know I can set browser.altClickSave in about:config to have it save the file when I click pressing ALT, but I need some solution that does not require user interaction.