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DMARC: How DNS Helps Protect Email Against Spamming And Phishing Attacks

Manchester, NH (February 4, 2013) – More than 144 billion emails are sent every day with a large portion of that being vital transactional emails sent from businesses across the world. As a result, the incentive for spamming and phishing attacks is on the rise. The only true way to know whether the emails in your inbox are coming from a verified sender is to use DNS.

Traditionally, DNS is associated with keeping websites performing fast and preventing downtime. However, Domain-based Message Authentication, Reporting & Conformance (DMARC) is a new way of authenticating email delivery by using the DNS. DMARC standardizes how email receivers perform authentication by using Sender Policy Framework (SPF) and DomainKeys Identified Mail (DKIM). These two technologies both store their records in DNS.

This works by allowing a sender to indicate that valid emails from their company are protected by SPF and/or DKIM. If the email that arrives does not pass either of those authentication methods, the receiver then knows to junk or reject the email, thereby avoiding harmful messages. This method eliminates the guesswork, which is why Dyn, the worldwide leader in Internet Infrastructure as a Service, recommends it to their email clients.

“We use DMARC on Dyn’s corporate mail and are advising customers on how to use it as well,” said Mike Veilleux, Dyn Director of Email Product. “The cost of having your passwords compromised is becoming so high that you can never be too safe. Using DMARC is just another security layer we advise.”

While this innovative use for using DNS to verify emails dates back to only 2011, Dyn has seen the connection between DNS and Email Delivery for years. In fact, DNS plays a major role in the Internet Infrastructure as a Service industry.

While everyone loves when a website deploys new technologies, features or operational practice, this increases the reliance on DNS. As a result, it quickly becomes a question whether a company will be able to get the same value from their own internal DNS servers or get more value from a widely dispersed – ideally anycast – and mature feature set like the one Dyn offers.

“People underestimate the importance of the DNS in everything they do online,” said Andrew Sullivan, Dyn Director of DNS Engineering. “The increased dependency on technology means an increased dependency on the DNS.”


Incorporated in 2001, Dyn is the worldwide Internet Infrastructure as a Service (IaaS) leader, powering Managed DNS, Traffic Management, Email Delivery & Email Reporting for more than four million enterprise, small business and personal users. With nearly 20 data centers around the world and industry-leading uptime for over 10 years, Dyn’s commitment to customer relationships and engineering excellence shines every day. Uptime is the Bottom Line.

Dyn Media Contact

Adam Coughlin | | 603.714.5798

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