Open .eml files in build mode in Outlook 2010

Question

I want my users to be able to open eml files in layout mode in Outlook 2010, by default it opens in readonly mode. Is there a way out?

Usage: we create email templates that users can download and configure before sending.

Answer 1

If you can add the "X-Unsent: 1" header to your .eml, it should open in Compose mode.

Answer 2

Works in Microsoft Outlook, but does not work on thunderbird.

A related discussion can be found here https://bugzilla.mozilla.org/show_bug.cgi?id=688284