Fifteen leading email service providers and tech companies have announced a joint effort to fight phishers.

Google (Nasdaq: GOOG), FacebookPayPalYahoo (Nasdaq: YHOO) and Agari are among the companies behind the Domain-based Message Authentication, Reporting and Conformance(DMARC) spec.

DMARC is a technical specification that standardizes how email receivers perform email authentication using well-known mechanisms.

“The inspiration behind DMARC was PayPal’s and Google’s attempt to stop phishing together, but they quickly realized the model they were pursuing could not scale,” said Daniel Raskin at Agari. That led to the formation of