We'd have to get the list
(here) then lookup their names in the Forums
here, then see if they have an e-mail addy.
I'll help sending e-mails out, but I won't do it by myself! We'll have to get organized here... A lot of these people don't have a username.
There are more than 650 unaffiliated people that have produced more than 1'000'000 structures.