Absolutely, the emails will be recovered. They could be in a number of places, including her smart phone and/or travel computer, assuming she had one as did Nikole Flax.
Emails would also be on the computers they were sent to. Certainly there were more than six.
Correct in that email could have been replicated and sent to multiple devices including smartphone. But any such emails have been deleted long ago - either intentionally or just by habit. I use my phone for alerting me on emails but never keep them on my phone. I delete them to reduce the clutter. Also I doubt backup tapes for email so long ago is still there without being overridden. The emails IMO are gone and will never be found. Just like that plane.