I don’t know about you, but I have a great dislike for HTML e-mail
which takes extra time to open (as Outlook starts up an instance of
the Internet Explorer engine) and is susceptible to going off
and downloading images and who knows what else from the web. Well,
it turns out that (finally) Microsoft added a “read as plain text”
feature into Outlook 2002 SP1 but you need to edit the registry to
enable it. See

OL2002: Users Can Read Nonsecure E-mail As Plain Text