Applescript to add email to todo.sh from Mail.app. If you use the `nav` plugin, you can open the email in Mail.app with `todo.sh nav ITEM#` from the cli.

todo.scpt

tell application "Mail"
	set theSelection to selection
	set theMessage to first item of theSelection
	set theURL to "message://%3C" & message id of theMessage & "%3E"
	set theTitle to subject of theMessage
end tell

set theTitle to do shell script "echo " & quoted form of theTitle & " | sed 's/'\\''//g'"

do shell script "/usr/local/bin/todo.sh a follow up on " & theTitle & ": " & theURL