The main purpose of DMARC is to give email domain owners a way to protect their domain from unauthorized use, also known as spoofing. By publishing a DMARC policy in their DNS records, domain owners can specify which mechanisms are used to authenticate email messages sent from their domain, and what to do if a message fails authentication. This allows receiving mail servers to check the authenticity of messages and prevent them from being delivered if they fail the authentication check.
DMARC works by allowing a domain owner to publish a policy in their DNS records that specifies which mechanisms, such as SPF and DKIM, are used to authenticate email messages sent from their domain. When a receiving mail server receives an email message, it checks the message’s headers to see if it includes a DMARC policy. If the message includes a DMARC policy, the receiving mail server will check the message against the domain owner’s published policy to see if it passes authentication checks (namely, SPF and DKIM). If the message fails authentication checks, the receiving mail server can take the action specified in the policy, such as quarantining or rejecting the message.
DMARC can be an effective tool against spam and phishing attacks that use spoofing to impersonate a legitimate domain. By implementing DMARC and regularly monitoring their DMARC reports, domain owners can help prevent their domain from being used in these types of attacks. However, it’s important to note that DMARC alone is not a complete solution for protecting against spam and phishing, and should be used in conjunction with DMARC, user awareness training and the implementation of secure email gateway.
Implementing DMARC can be somewhat complex, as it involves publishing a DMARC policy in your DNS records and regularly monitoring your DMARC reports. If you’re not familiar with DNS and email authentication mechanisms, it’s ideal to work with an organisation like Sendmarc to help set up your DMARC policy. The Sendmarc tools also give you the visibility needed to monitor the progress on all your active domains (or customer domains) on an ongoing basis. Additionally, Sendmarc provides tools which make the management of SPF, DKIM and DMARC much easier.
SPF, or Sender Policy Framework, is an email authentication protocol that is designed to prevent spammers from sending messages with forged sender addresses. It works by allowing the owner of a domain to publish a list of IP addresses or subnets that are authorized to send email on their behalf. When a receiving mail server receives an email message, it can check the message’s headers to verify that it was sent from an authorized IP address. This helps to prevent messages with forged sender addresses from being delivered.
DKIM, or DomainKeys Identified Mail, is an email authentication protocol that is designed to prevent unauthorized modifications to the contents of an email message. It works by using cryptographic signatures to verify that the message has not been altered in transit. When a message is sent, the sender’s mail server generates a digital signature for the message, which is added to the message headers. The receiving mail server can then use the sender’s public key, which is published in the sender’s DNS records, to verify the digital signature and ensure that the message has not been tampered with.
SPF and DKIM are complementary email authentication protocols and are often used together to provide a more robust defence against spam and phishing attacks. SPF is focused on preventing forged sender addresses, while DKIM is focused on preventing unauthorized modifications to the contents of a message. By implementing both SPF and DKIM, a domain owner can help ensure that their messages are delivered to the intended recipient, and that the contents of the message have not been altered in transit.
SPF and DKIM can be effective tools against spam and phishing attacks that use forged sender addresses or tampered-with message contents. By implementing both SPF and DKIM and regularly monitoring their SPF and DKIM records, domain owners can help prevent their domain from being used in these types of attacks. However, it’s important to note that SPF and DKIM alone are not a complete solution for protecting against spam and phishing, and should be used in conjunction with DMARC, user awareness training and the implementation of secure email gateway.
Sendmarc and your current Secure Email Gateway (SEG) complement each other in multiple ways. By implementing DMARC with Sendmarc, you will provide your SEG with additional signals to effectively identify and reject impersonation emails.
Additionally, Sendmarc will protect your domain from impersonation attempts outside the perimeter of your SEG. This means that every company and individual that receives mail from your domain will be able to easily distinguish between legitimate mail and attempts by attackers to impersonate your organization. While your SEG is a crucial component of your security strategy, Sendmarc enhances that protection by ensuring that only legitimate mail is delivered, both to your organization and to the rest of the world.