What is DMARC and How to Set It Up for Your Organization?

DMARC assists email receivers in determining if a message “aligns” with their knowledge of the source. It ensures that emails sent from a specific domain are legitimate, reducing the risk of phishing attacks.

Today, we are dominated by digital communication and email security has become crucial against cyber threats. Phishing attacks, have emerged as a challenging vulnerability in email systems to compromise sensitive data and put businesses at stake.

DMARC, or Domain-based Message Authentication, Reporting, and Conformance is a robust email authentication protocol. It is a TXT record kept in DNS that allows email recipients to verify the validity of incoming messages. This tool integrates with a company’s current inbound authentication procedure.

DMARC provides a comprehensive framework. It goes beyond traditional authentication methods to enhance email security. Before getting a Verified Mark Certificate (VMC), you must first satisfy DMARC.

With DMARC implementation, we will cover the basics of DMARC, its role in enhancing email security, and step-by-step DMARC setup. Whether you’re an IT professional, a business owner, or someone who ensures the security of your company’s communication channels, this blog is tailor-made for you.

Prerequisites for DMARC Set Up

SPF (Sender Policy Framework): SPF is a DNS-based email authentication protocol that helps protect against email spoofing. SPF records are published in a domain’s DNS settings and specify which mail servers are authorized to send emails on behalf of that domain.

DMARC begins by leveraging SPF, which designates authorized mail servers for a domain. If the sender’s IP aligns with the SPF record, it passes the first authentication check.

How To Set Up SPF?

Sender Policy Framework (SPF) acts as a security measure to prevent unauthorized email senders. This mechanism makes it easier for DNS servers to communicate with one another. SPF prevents malicious actors from sending emails on your behalf.

SPF enhances email authentication by defining which IP addresses can send emails from your domain. Without an SPF, a recipient’s DNS server might struggle to verify the true sender of an email. The commendable features make SPF a crucial component in preventing email impersonation.

Setting up an SPF record is a pivotal step in fortifying email security:

To begin, check your current SPF record using tools like MxToolbox or Google Apps Toolbox. These tools provide insights into your SPF status or notify you if it isn’t configured yet.

The steps vary as per your domain host!

Create a new TXT record with the SPF information. The format of an SPF record typically starts with the version number “v=spf1” followed by mechanisms and modifiers.
Directly specify IP addresses allowed to send emails for your domain using the ip4: (IPv4) or ip6: (IPv6) mechanisms.
Example: v=spf1 ip4:192.0.2.1 ip6:2001:db8:0:1:1:1:1:1
Add an “include” tag for each authorized external organization. They send emails on your domain’s behalf, such as include:thirdpartydomain.com. For example, if using Google Apps, include Google’s SPF record using include:_spf.google.com.
Specify the default action for emails from sources not explicitly allowed. Common actions include -all (hard fail, reject), ~all (soft fail, mark as spam but deliver), or +all (allow all sources, not recommended due to potential misuse).

After setting up your SPF record, it may be displayed as:

v=spf1 ip4:192.0.2.1 ip6:2001:db8:0:1:1:1:1:1 include:thirdpartydomain.com -all

A comprehensive SPF record ensures a robust shield against unauthorized email senders. It also supports your overall email security posture.

DKIM (DomainKeys Identified Mail): DKIM is an email security protocol that ensures messages are not altered while being transmitted.

DMARC incorporates DKIM, where emails are signed with cryptographic keys. If the recipient’s server verifies the DKIM signature against the public key in DNS, it passes the second authentication layer.

How To Set Up DKIM?

DomainKeys Identified Mail (DKIM) provides the same goal as SPF: to prevent email impersonation.

This standard enables signing your emails to allow the recipient’s server to verify the sender’s validity. Implementing DKIM on your DNS server improves email security by informing recipients that the message is truly from you.

To create a DKIM record, generate a public key using your email provider’s admin panel.
NOTE: For Google Apps users, DKIM signatures may be deactivated by default, requiring explicit activation in the Google Admin panel.
Once you’ve got the public key, add the produced TXT entry to your DNS entries.
Finally, enable email signing to send messages that include an encrypted signature from your private key.

Now, you are ready to strengthen your email infrastructure. Give your receivers extra confidence in the integrity of your delivered emails.

Ensure SPF and DKIM are already set up and authenticating messages for at least 48 hours before configuring DMARC.

DMARC Enforcement Policy

A DMARC Enforcement Policy, or DMARC compliance, is vital to implementing Domain-based Message Authentication, Reporting & Conformance (DMARC) within an organization.

Organizations enable email receiver systems with DMARC policy. It differentiates between legitimate and fraudulent emails. If an email does not originate from an approved domain, the DMARC policy alerts the receiver systems. It handles guiding the appropriate response, thereby isolating potential threats.

DMARC enforcement is a critical step in setting up DMARC to protect your organization from email fraud. While a DMARC policy set to –

p=none: provides valuable raw data, only at enforcement. Emails pass through without authentication restrictions to the intended recipient’s inbox.

p=quarantine: Unauthenticated emails are diverted to the recipient’s spam or junk folder.

p=reject: the true anti-impersonation and anti-phishing benefits emerge here. Unsuccessful authentication results in the email being discarded, never reaching the recipient.

At enforcement, only authorized emails from your domain are delivered, while unauthorized ones are either sent to spam or deleted. Internet Service Providers consider your DMARC status in making delivery decisions. Unfortunately, many domains haven’t implemented DMARC enforcement yet. Studies show that 75-80% of domains remain at the p=none stage.

By combining SPF, DKIM, and DMARC policies, this comprehensive email authentication framework safeguards against phishing attacks, ensuring secure and trusted communication.

Now that you understand the importance of DMARC enforcement policies, you’re ready to delve into the configuration process. Let’s move on to a detailed guide for implementing DMARC in your organization.

Step-by-Step Guide to DMARC Implementation

Setting up DMARC DNS records

Let us begin setting up DMARC to DNS as a crucial step for your email security –

STEP 1: DNS Login & TXT Record Addition

Begin by logging into your DNS provider and locating the area to add a TXT record.
Enter “_dmarc.your-domain.com” (replace “your-domain” with your actual domain) as the hostname.
Utilize the recommended tags such as v=, p=, fo=, rua, and ruf for a comprehensive setup.
- v=DMARC1: This specifies the DMARC version (currently 1).
- p=none: This sets the initial policy to “none” for monitoring purposes. Emails will still be delivered, but you’ll receive reports on authentication failures.
- fo=1: This enables forensic reporting, providing detailed information about authentication failures.
- rua=mailto:dmarc_reports@yourdomain.com: This tells email servers where to send aggregate reports about DMARC failures. Replace “dmarc_reports@yourdomain.com” with a valid email address you can access.
- ruf=mailto:dmarc_alerts@yourdomain.com: This tells email servers where to send forensic reports for individual failures. You can use the same email address as “rua” or create a separate one for alerts

STEP 2: Version & Initial Policy Setup

Specify the DMARC version with v=DMARC1 and set the initial policy to p=none for monitoring.
Employ fo=1 for forensic reporting and input your email address for rua (aggregate reports) and ruf (forensic reports).
The order of your DMARC entries is essential for clarity.

STEP 3: DMARC Record Example & Address Validation

Here’s an example:
v=DMARC1; p=none; fo=1; rua=mailto:dmarc_reports@yourdomain.com; ruf=mailto:dmarc_alerts@yourdomain.com;
Ensure the addresses provided for rua and ruf are valid for receiving reports.

STEP 4: Submission & Monitoring Phase

Lastly, submit your DMARC record with your DNS host provider and allow at least a week for monitoring before implementing stricter policies like p=quarantine or p=reject.
This phased approach ensures proper authentication and enhances the effectiveness of your DMARC setup.

Configuring DMARC enforcement policies (Quarantine vs. Reject)

How To Set Up DMARC Quarantine Policy?

To set up DMARC quarantine enforcement, carefully configure your policies to control the fate of non-compliant emails.
If the receiver maintains a quarantine mailbox, messages will be directed there, leaving the administrator with the pivotal decision to deliver or discard them.
Alternatively, recipients hosting mailboxes may choose to divert non-compliant emails to the spam folder, empowering users to decide whether to move them to the inbox.
Employing aggressive anti-spam filtering enhances security by recognizing quarantined messages as potentially spam-like, allowing additional scoring and potential blocking.
While some view quarantine as a gradual DMARC testing option, it demands meticulous configuration to prevent legitimate emails from being wrongly marked, safeguarding your brand from associations with undesired emails.

How To Set Up DMARC Reject Policy?

Implementing a DMARC “p=reject” policy is a swift and effective strategy to halt malicious emails at the source. This approach ensures that intended recipients remain blissfully unaware of potential threats, as malicious emails are outright blocked without entering spam or quarantine folders.
The proactive nature of “reject” prevents end-users from falling victim to phishing attempts, safeguarding them from clicking on harmful links or opening malicious attachments. While this provides robust security, organizations should be cautious about legitimate emails failing authentication, as these would also be rejected.
To mitigate this, employing a reporting system is crucial for ongoing monitoring. It guarantees swift identification of any legitimate email delivery issues. With this, you can prevent potential setbacks in marketing initiatives or engagement opportunities.

Optimizing Email Security with ‘Reject’ in DMARC Policy

Choosing “reject” over “quarantine” in your DMARC policy gives a more effective defense against phishing and impersonation. You can start with ‘quarantine’ to track any legitimate email delivery issues before implementing ‘reject’.

With “reject,” you strive for a stronger consequence, increasing the possibility that recipient hosts will remove unauthorized communications. To improve email security, set DMARC settings to “reject,” which emphasizes a proactive approach to suspected risks.

Unlock the Power of DMARC records for Email Security Insights

DMARC reports provide vital insights into your email environment. These insights include information about sending volumes, sources, DMARC policy, and alignment settings. The reports provide a complete picture of your domain infrastructure. They are also an effective tool for recognizing emails. They combat such fraudulent emails that falsely claim association with your domain.

The DMARC configuration, published as a DNS TXT record, instructs recipient mail servers. It regulates how to handle communications that do not have SPF and DKIM alignment. These reports, which get back to domain owners, shed insight into message authenticity. It allows for the continuing improvement of email security by identifying authentication successes and possible flaws.

Once you’ve configured and enforced your DMARC policy, it’s crucial to ensure your DMARC record is functioning properly. Verifying your domain is a quick and easy process that doesn’t require any coding. Let’s see how to do it.

Verifying Procedure for DMARC records

Several free DMARC record inspection programs will assist you in validating that your TXT records were properly published.

Select your preferred DMARC record inspector or lookup tool.
Input your domain, then click the “Scan Your Domain,” “Scan Now,” or “Authenticate Your Domain” option. It examines your domain and provides thorough results.
Enter your domain name and press the “Scan Now” tab.

The DMARC checker will scan your domain and return a thorough report with a score of 1 to 10. A score of 7 or less out of 10 indicates that the site owner should improve their authentication mechanisms.

Use this method to safeguard your domain when sending emails (transactional or corporate.)

As a result, choose a suitable DMARC record analyzer for testing your domain. After completing your configuration, confirm that your text document is valid and published.

In Conclusion

DMARC emerges as an essential strategy in strengthening email security against phishing and impersonation threats. By combining SPF, DKIM, and DMARC policies, organizations establish a robust defense mechanism. This step-by-step guide offers practical insights for implementation, enabling businesses to mitigate risks and ensure trusted communication.