text/html; firefox -new-tab %s & sleep 5; test=test -n "$DISPLAY"; 
#
# for mutt to view html e-mails
# text/html; w3m -I %{charset} -T text/html; copiousoutput
text/html; html2text %s; copiousoutput

application/pdf; evince %s; copiousoutput
# text/calendar; ~/.mutt/scripts/vcalendar-filter; copiousoutput
#text/calendar; mutt-ics; copiousoutput
#application/ics; mutt-ics; copiousoutput 
application/*; xdg-open %s