Complex sentence: DomainKeys is an e-mail authentication system designed by Mark Delany of Yahoo!, Russ Nelson and John Levine of qmail, and Eric Allman of sendmail (and others) for verifying the DNS domain of an E-mail sender and the message integrity.
Split into simpler sentences: DomainKeys is an e-mail authentication system designed by Mark Delany of Yahoo!. The goal of DomainKeys is to verify the DNS domain of an E-mail sender and the message integrity.