Free Robust Email Validation API

The guys at Mailgun are taking a very interesting approach at the ever-lasting problem of proper Email validation: Given an arbitrary address this service validates address based off syntax checks (RFC defined grammar), DNS validation, spell checks, and if available, Email ServiceProvider (ESP) specific local-part grammar. They’re relying on formal grammar and not on regex like the rest of us, which is perhaps the more intriguing aspect of the project. »