3.7.1 For use with Internet Explorer

You can use Emacs as the editor for composing mail for ‘mailto:’ links, reading Usenet for ‘news:’ links, and viewing source. The following registry entries control this:

• Mail
  • Key: HKCR\mailto\shell\open\command\(Default)
  • Value: emacsclientw -e "(message-mail (substring \"%1\" 7))"
• News
  • Key: HKCR\news\shell\open\command\(Default)
  • Value: emacsclientw -e "(gnus-fetch-group (substring \"%1\" 5)"
• View Source
  • Key: HKCR\htmlfile\shell\edit\command\(Default)
  • Value: emacsclientw "%1"

Thanks to Jason Rumney and Sigbjorn Finne for these tips.