Universities in Germany and probably many other countries don’t have special e-mail addresses. I guess you will either have to verify manually (if there is indeed some kind of college or university behind the address) or just not accept those submissions.
That would help. Many German universities have rudimentary English versions, which makes things easier, too. I suppose it's enough to search the university's name and "email", though. I found some email adresses of my university that way, anyway. Thanks for doing this - I (and the other students, I bet) appreciate it a lot.
