Their new organization has designed a system, called DMARC, for authenticating emails from legitimate senders and weeding out fakes.

NEW YORK — Google, Microsoft, Facebook and other big tech companies are jointly designing a system to combat email scams known as phishing.

Such scams try to trick people into giving away passwords and other personal information by sending emails that look as if they come from a legitimate bank, retailer or other business.

When Bank of America customers see emails that appear to come from the bank, they might click on a link that takes them to a fake site mimicking the real Bank of America’s. There, they might enter personal details, which scam artists can capture and use for fraud.

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To combat that, 15 major technology and financial companies have formed an organization to design a system for authenticating emails from legitimate senders and weeding out fakes. The new system is called DMARC — short for Domain-based Message Authentication, Reporting and Conformance.

It builds upon existing techniques designed to verify that an email actually came from the sender in question. The problem is there are multiple approaches and no standard way of dealing with emails believed to be fake.

The new system addresses that by asking email senders and the companies that provide email services to share information about the messages they send and receive.

In addition to authenticating their legitimate emails using the existing systems, companies can receive alerts from email providers every time their domain name is used in a fake message. They can then ask the email providers to move such messages to spam folders or block them outright.

According to Google, about 15 percent of non-spam messages in Gmail come from domains protected by DMARC. This means Gmail users “don’t need to worry about spoofed messages from these senders,” Adam Dawes, a product manager at Google, said in a blog post.

“With DMARC, large email senders can ensure that the email they send is being recognized by mail providers like Gmail as legitimate, as well as set policies so that mail providers can reject messages that try to spoof the senders’ addresses,” Dawes wrote.

Work on DMARC started about 18 months ago. Now other companies can sign up with the organization, whether they send emails or provide email services.

For email users, the group hopes DMARC will mean fewer fraudulent messages and scams reaching inboxes.

The group’s founders are email providers Microsoft, Yahoo, AOL and Google; financial-service providers Bank of America, Fidelity Investments and PayPal; online service companies Facebook, LinkedIn and American Greetings; and security companies Agari, Cloudmark, eCert, Return Path and the Trusted Domain Project.

Google uses it already, both in its email-sender and email-provider capacities.

The heft of the companies that already have signed on to the project certainly helps, and its founders hope it will be more broadly adopted to become an industry standard.