DMARC is one of the most crucial email authentication protocols in the world right now. It combines two previously established protocols, namely SPF and DKIM, and brings a new tier of email authentication and verifiability to all domains.

Despite the universal benefits of applying DMARC to all domains, only a relatively small percentage of email domains worldwide have DMARC implemented on them. Moreover, most people do not understand how DMARC protects client domains from spoofing and by extension, prevents consumer phishing.

If you have been wondering how you should implement your DMARC on your servers, this blog is where you can get all the information you need. Read on to know about DMARC’s anti-spoofing features, how you can use them to prevent consumer phishing, and the additional benefits you can get from DMARC implementation.

Five Important Factors Affecting DMARC’s Anti-Spoofing Features

1.SPF is Your First Basic Vanguard
The Sender Policy Framework or SPF protocol uses a specially formatted TXT record in the domain DNS to uniquely identify each sender. This is part of the mail ‘FROM’ header (or return-path, envelope ‘From’, or return email address) if you see any email in its basic SMTP transaction. This record contains an identification attribute for denoting the specific servers that are authorized by the domain owner to send emails. This attribute mentions the IP address in question and hostnames and may also contain the SPF record of other domains.
If you just have SPF, then you do not actually check if an email is authentic or not. Rather you will simply check the SPF record via a DNS lookup and see if it’s there or not. Naturally, this is not enough to validate if an email is authentic since not all domains will contain an SPF record that matches the relevant policy parameters you want. Further, if you have more than 10 DNS lookups on an email, the incoming email is automatically invalidated. This is a problem because authentic emails may also get rejected due to the SPF DNS lookup limit.

2.DKIM Brings Keypaired Authentication to Emails
The DKIM protocol is combined with SPF to make up DMARC, and it is designed to confirm the validity of the email sender. The protocol works by generating a dual key with one private and one public for each outgoing email from its native server. Once the receiving email server gets the sent email, it checks if the header contains a DKIM signature field. If the field exists and the key matches, the protocol checks the DNS record for the DKIM public key to validate the signature. If the signatures on both sides are validated, then the DMARC authentication process initiates.

It is possible that a hacker may steal the private key using a compromised system. That is why admins should change DKIM keys regularly. In case, you have an email service provider, your DKIM keys are changed automatically by the provider. While DKIM does not prevent spoofing directly by itself, it can combine with SPF to ensure that the domain and the email it comes from are legit. That is why it cannot provide complete email authentication security by itself.

3.DMARC Brings SPF and DKIM Together
DMARC takes both SPF and DKIM and combines their operations to provide a much more robust email authentication process. It authenticates the SPF requisite via the Mail FROM and the ‘From’ domain header. As for DKIM, the protocol checks ‘From’ from the SMTP email header and the DKIM signature d=field. In technical terms, this is called aligned.
After this process is completed, DMARC checks the alignment in the SPF and DKIM protocols. In particular, it combines the ‘From’ field from both and ensures that they check from the same place. This brings together the two protocols and allows for more effective authentication. In this context, DKIM alignment has more relevance than SPF because email forwarding removes SPF identification.

4.DMARC Policies are Paramount
DMARC’s role doesn’t just stop at alignment. In fact, the alignment check will not begin until the admins add a policy (p=) tag to their DMARC record. Once they do this, they will be able to tell any receiving domains how to read the emails and authenticate them. Broadly speaking, there are three types of DMARC policies – none, quarantine and reject.
The first is used for simply observing email traffic and understanding where threats are coming from. The second is used to flag any email that fails the DMARC check, and users will be warned of the suspicious email. These types of emails are usually sent to the spam folder unless the policy is set otherwise. The third is set when the admin is certain they want to lock down their domain and allow only select IPs to send authorized emails.
DMARC policies are important because they allow users to create a unique profile for their domain. This also enables them to get the most out of their DMARC protocol while giving the best representation of their company through every email.

5.DMARC Records and Reports
DMARC records and reports are important tools for understanding how your email domain is working. Both of them provide important benefits to domain admins and email receivers. There are two types of reports – aggregate reports and forensic reports. These can help provide information to admins and they can send aggregate reports over to linked accounts for easy utilization of data.

What Is DMARC’s Primary Anti-Spoofing Process?
Using data aggregated from DMARC, you can find out which IPs are trying to spoof your domain and blacklist them. Further, using DMARC policies can help you list out the IPs that have permission to send emails from your official domain. This ensures every email you send is authentic and so, your reputation grows over time. This helps in ensuring you get the maximum value from all emails and they get the benefit of direct delivery thanks to authentication and a rise in domain reputation.

How Should You Approach Your DMARC Implementation
DMARC is a great email authentication protocol to bring all the previous protocols into alignment. It is used by countless big IT and tech businesses around the world. If you have an on-site email server, then getting DMARC can give you crucial cover over your cybersecurity weak spots. If you have SPF or DKIM or both, you are still not getting the most value for your money. Get DMARC at EmailAuth for the best use case for all your protocols. A smartly designed interface, easy report generation, and many customization options make EmailAuth one of the best apps for DAMRC installation and utilization. Get it now!

Author's Bio: 

EmailAuth.io is part of the Infosec Ventures group and our core value lies in taking care of your most valuable digital asset: Email.