EML mail format
view EML by using bash
You could extract the html body and view the results in a web browser:
cat ~/bin/eml2html
email="$1"
sed -n '/<html>/,${$!p}' "$email" >/tmp/temp.html
firefox "file:///tmp/temp.html"
rm /tmp/temp.html
chmod +x ~/bin/eml2html
tested on an html email saved using Thunderbird.
copy it to your ~/bin/ directory