Swot is a community-driven or crowdsourced library for verifying that domain names and email addresses are tied to a legitimate university of college - more specifically, an academic institution providing higher education in tertiary, quaternary or any other kind of post-secondary education in any country in the world.
I actually used the swot database for the site. If anyone is interested this gist will download the swot repo and generate a dictionary of the email --> school/university in python:
Ops, I meant to ask how they were validating academic addresses. I'm actually a postdoc, but my university domain is @upv.es, and I've found that sometimes it doesn't get recognized in American websites which expect a .edu for claiming academic discounts or things like that.
@bringtheaction comment mentioning SWOT is an interesting solution. Although the name of my institution is outdated! I'll send a PR.
The important part here is "usually". It should be stressed that using lists (such as SWOT mentioned in another comment here) can add to the bias towards US and other well-known universities.
I have been involved in academia for 10 years now, and I never held an email address that would match against the SWOT list.