The DMARC email security protocol has become a critical weapon in the fight against email spoofing and impersonation. But what is DMARC, exactly, and what are its benefits and limitations in preventing these sophisticated attacks?
DMARC stands for Domain-based Message Authentication, Reporting and Conformance, a protocol for authenticating that an email received from a specific domain is legitimately using that domain and is not fraudulent.
Sending a fraudulent email from a legitimate domain is one of the techniques used by cyber criminals to trick users into divulging sensitive information or wiring money to fraudulent accounts. DMARC email security protocols can help to prevent this specific type of attack by allowing senders to notify recipients that their messages are protected by SPF and/or DKIM authentication and providing instructions for what to do if an email passes neither one of those authentication methods. Essentially, DMARC email security takes the guesswork out of the way that receivers handle failed messages, minimizing the recipient's exposure to potentially fraudulent email and helping to protect the sender's domain from being used fraudulently.
While DMARC email security can be highly effective at stopping a particular kind of attack, cyber criminals are very adept at finding many ways of breaching an organization's security. That's why so many companies turn to Mimecast for solutions that combine DMARC email security with other highly effective and multilayered defenses.
Mimecast offers an all-in-one solution for email security, archiving and continuity that is available as a cloud-based subscription service. With Mimecast's SaaS email security offering, organizations can easily roll out security defenses company-wide without capital expense or long lead times.
The Mimecast Secure Email Gateway is the heart of Mimecast email security services. In collaboration with DMARC Analyzer, an alliance partner, Mimecast uses the DMARC email security protocol to give customers insight into any unauthorized use of their domain via email, enabling them to move to DMARC compliance and a DMARC reject policy faster and with more confidence. Designed to enable self-service, the DMARC email security with Mimecast helps organizations to simplify DMARC enforcement to protect their domain against misuse and to prevent an email data breach for recipients.
In addition to services for authentication using DMARC email security protocols, Mimecast also provides tools to identify other techniques used in impersonation attacks, including:
With Mimecast, organizations can adopt a multilayered approach to email security that provides maximum protection against an evolving threat landscape.
Learn more about DMARC email security with Mimecast.
What is DMARC email security?
Domain-based Message Authentication, Reporting & Conformance (DMARC) is a protocol that relies on Sender Policy Framework (SPF) and DomainKeys Identified Mail (DKIM) to determine whether an email message is legitimate or not. DMARC enables mail servers to determine whether email received from a domain is properly authenticating against these standards and to block email that failed to authenticate. By stopping illegitimate messages, DMARC email security helps to protect organizations from phishing attacks and other types of email-borne cybercrime.
How does DMARC email security work?
DMARC enables an organization to publish policies to its DNS record that define its practices for email authentication and provides instructions for receiving mail servers about how to enforce them. Essentially, DMARC helps receiving mail servers determine if an incoming message “aligns” with what is known about the sender, and how to handle messages that don’t align.
Specifically, DMARC enables receiving mail servers to check for alignment between the “header from” domain name and the “envelope from” domain name that is used during SPF authentication, and alignment between the “header from” domain name with the “d= domain name” in the DKIM signature.
If a message fails both SPF and DKIM authentication and alignment, receiving mail servers can check the sender’s DMARC email security policy to decide whether to accept, block or quarantine the email message. DMARC also reports the outcome of this decision back to the sending domain owner, providing clearer insight into messages sent from the domain.
Who can use DMARC email security?
DMARC can be implement by any organization. It is a free and open protocol, with policies published in the public Domain Name System (DNS), and requires no licensing.
What are the benefits of DMARC email security?
Benefits of implementing DMARC email security include:
Will DMARC email security prevent spoofing?
DMARC email security can prevent direct domain spoofing, which mimics the exact sending domain of an organization. It cannot, however, block look-alike domains (domains that are spelled slightly differently), spoofed accounts (emails that use a name similar to that of a trusted party) or newly registered domains that haven’t yet been associated with malicious activity. Consequently, many organizations opt for a multilayered approach that augments DMARC email security with a variety of other types of defenses.