I was contacted off-list about this situation by someone who wants to remain anonymous but has given me permission to forward their input to the list. I am not a copyright expert and this isn't professional legal advice. It would be interesting to hear what WMF Legal thinks about republishing emails, both from the privacy angle and the copyright angle.
Thanks,
Pine
Pine, why not just suggest she invite respondents to adopt a free license, instead of reinventing the wheel? Like..."I'd like to have the right to republish these stories, but it's up to the respondents. If you're willing, please explicitly state that you release these under the CC-BY-SA 3.0 license; or, if you'd rather not be identified, under the CC-0 license."
We have these tools for a reason :)