I have sent a new version of LookOut to addons.mozilla.org (AMO). Of course I am still waiting for them to approve the last version I submitted. This new version fixes a metadata reading bug and added RTF decoding/decompression. It would be nice if the RTF could be viewed inline but at least it is accessible. TNEF encapsulated RTF and HTML body text (as opposed to an explicit attachment) will now show as attachments named body_part_#.rtf or body_part_#.html. Until the AMO folks get around to it you will find the LookOut 1.2 xpi in the project website.

Enjoy,
Aron