Mimecast provides DNS authentication services that include SPF, DKIM and DMARC protocols to prevent spoofing and impersonation. Learn More.

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    Protecting email data with DMARC.

    Domain-based Message Authentication, Reporting and Conformance (DMARC) is protocol for email authentication that helps an organization to prevent cyber criminals from illegitimately using its domain name to initiate email spoofing or impersonation attacks.

    What is DMARC designed to do? The DMARC email security standard enables senders to indicate that email originating from their domain is protected by SPF and/or DKIM, and provides instructions for how receivers should treat messages that don't pass either of these authentication methods. Consequently, DMARC minimizes the impact of fraudulent or harmful messages for recipients while protecting the integrity of the sender's domain. DMARC also enables recipient organizations to inform sender's about email that passes or fails DMARC compliance.

    However, DMARC alone cannot protect an organization from a wider range of malware-less impersonation attacks – it only addresses illegitimate use of a legitimate domain name, and attackers frequently use slightly different domain names that appear almost identical to the original, which DMARC cannot stop. That's why, when seeking the strongest levels of email data protection, more organizations today are turning to solutions from Mimecast that combine DMARC with a multilayered approach to stopping an email data breach.

    Protecting email data with DMARC.

    Mimecast solutions for DMARC email security.

    Mimecast provides a cloud-based service that includes a suite of solutions for email security, archiving and continuity that help to simplify management of business email and reduce the cost and complexity of protecting email data from attackers.

    At the center of Mimecast email security offerings is the Mimecast Secure Email Gateway. Combining sophisticated threat intelligence and multilayered detection engines, this Mimecast service provides DNS authentication services that include SPF, DKIM and DMARC protocols to prevent spoofing and impersonation. Mimecast provides 360-degree email channel visibility, reporting and validation that provides organizations with insight into any unauthorized use of their domain, allowing them to reject illegitimate emails more quickly and with greater confidence.

    Mimecast solutions for DMARC email security.

    Beyond DMARC: additional services for combating email fraud.

    In addition to DMARC-based authentication, Mimecast provides a suite of services that helps to protect against other types of sophisticated techniques used in ransomware, spear-phishing and impersonation attacks. These include protection against:

    • Malicious URLs. Mimecast scans every link in every email on every click. Using third-party and proprietary threat intelligence, Mimecast evaluates the security of every URL and blocks access to suspicious links.
    • Weaponized attachments. Mimecast applies deep inspection analytics on files attached to email, converting suspicious attachments to a safe format or sandboxing them until they can be deemed safe.
    • Internal threats. Mimecast scans all internal email for signs of potential of data leaks or malicious intent, blocking or identifying suspicious messages as well as sensitive data being sent out of the organization.

    Learn more about DMARC authentication with Mimecast.

    Beyond DMARC: additional services for combating email fraud.

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    What is DMARC security?

    DMARC is the Domain-based Message Authentication, Reporting & Conformance protocol for email authentication, policy and reporting. DMARC makes it easier for email recipients to check that a sender’s email is legitimate, and to know what to do with an email that can’t be authenticated. Ultimately, DMARC adds another layer of protection to guard against the use of illegitimate email and cyberattacks.

    Why is DMARC important?

    Email phishing attacks are responsible for 90% of data breaches today, and the number of phishing attempts continue to grow each year.[i] DMARC can help to prevent certain kinds of cyberattacks by preventing email sent from illegitimate users from being delivered to the inboxes of users who may inadvertently open the email, click on a link or divulge sensitive information that can be used to hack accounts, access systems or commit theft of data and money.

    How does DMARC work?

    DMARC builds on Sender Policy Framework (SPF) and DomainKeys Identified Mail (DKIM), two existing email authentication techniques. A DMARC policy lets a sending organization indicate that their messages are protected by SPF and/or DKIM, and lets a recipient’s email system know what to do if neither of those methods work when authenticating the email. When configured correctly, DMARC can successfully prevent unauthorized senders from sending mail using an organization’s domain.

    Here’s how DMARC works:

    1. The administrator of a domain publishes a DMARC record as part of the domain’s DNS records that defines its email authentication policies and lets recipient mail servers know what to do when an email violates these policies.
    2. When an inbound email server receives an email, it checks for three things:
      1. Does the email’s DKIM signature validate?
      2. Did the email come from an IP address that is allowed by the sender’s SPF records?
      3. Do the headers in the message align?
    3. If the message cannot be authenticated, the receiving email system uses the sender’s policies to decide whether to accept, reject or quarantine the message.
    4. The receiving mail server reports the outcome of authentication to the sending domain owner.

    Does Gmail use DMARC?

    Gmail supports DMARC, but the protocol must be established by an organization’s email administrators, and SPF and DKIM protocols must be set up before DMARC can be implement it. Consequently, DMARC protection in Gmail is highly dependent upon correct configuration by a domain’s email administrators.

    Does DMARC stops spoofing?

    DMARC can prevent some kinds of spoofing – for example, the illegitimate use of an actual domain. But it offers no defenses against spoofing attacks that use look-alike domains, newly registered domains, display name spoofing or reply-to mismatches. For this reason, organizations wishing to achieve maximum protection against email attacks often choose to adopt a multilayered approach to email security that involves a broad range of defenses.



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