Another research resource for you: Snov.
What does it do? You can find a list of every single domain email address belonging to a specific website, as well as get a list of every single person associated with it. This is supposed to be for networking and creating marketing leads, but... y'know. We can get creative here.
It is a plugin for Chromium browsers:
https://chrome.google.com/webstore/detail/email-finder-by-snovio/einnffiilpmgldkapbikhkeicohlaapjOne caveat: You do have to provide a phone number to sign up, but it doesn't actually get verified. I made one up. ;)
It is very, VERY handy.
Here's the dashboard for the Bill & Melinda Gates Foundation: