Domain-based Message Authentication, Reporting, and Conformance (DMARC)

DMARC or Domain Message Authentication Reporting and Conformance policy is the latest authentication tool. It supports both the SPF and DKIM authentication mechanisms. It combines the two methods and specifies what should happen when all authentication mechanisms fail. If any of the authentication mechanisms pass (i.e. SPF or DKIM) then DMARC passes. If none of them pass, then what should happen? Instructions might include marking the message as quarantined or rejecting the message completely.

DMARC also provides a feedback loop so senders can monitor whether emails that appear to be originating from their domains are conforming with the policy or not. You can request failed authentication results to be sent back to you; though this isn't necessarily enforced.

How to Create your DMARC Record

The DMARC Record is a DNS Record for your Internet Domain Name. At this time we recommend using MX Toolbox's DMARC Record Generator to create a DMARC record to put you your DNS records.

There is a very basic DMARC record that you can add to your DNS right now, that will ensure you are compliant with the current requirements to have this record. The DNS Record for a DMARC entry is prefaced with _DMARC., as in the following example:

See also..

• E-mail Authentication
• Sender Policy Framework (SPF)
• DomainKeys Identified Mail (DKIM)
• IP-based Reverse Address Validation (IP-REV)