LookingGlass aims to make forward secret, pseudonymous email as easy as downloading a disk image.
Boot it on a Raspberry Pi, or Virtualbox. Run it from your web browser.
Tech specs, for the gearheads.
Edit: download flakiness has been shored up with groaning timbers, yarr. Thanks fer ye interest.
Edit2: torrent for the VMDK image here
So how is this different than Pond?