we're building a little addon to send out mass mails to our community, but we're unsure which email to take.

U_RegEmail might be outdated, U_Email might be cleared out or fake, and the field U_Fakeemail speaks for itself!

I think U_Email should initially be set the same value as U_RegEmail, users should not be able to clear it out or change it directly, a verification via email just like here with opentopic would be very useful.

After all, if someone doesn't want to receive our newsletter U_AdminEmails, which we'd check first.

flint
flint@poisonfree.com

additional thought:
you could make it even more simple for users, by replacing U_Fakeemail with a checkbox "display email address in public".

flint
flint@poisonfree.com