Rated 5 out of 5 stars

by Charles B. on Oct. 18, 2013 ·

This works great for me in Thunderbird 24 after a small tweak. Close Thunderbird, then delete (or rename) your mimeTypes.rdf file, then start Thunderbird. I think I had associated application/tnef with something else before, causing the suggested fix below (adding to mimeTypes.rdf) to fail for me.