Email spoofing and phishing are major security threats, and DMARC is a key tool in the fight against them. DMARC stands for “Domain-based Message Authentication, Reporting & Conformance” and is an email authentication protocol
If you want to know what a DMARC record is and how it works, you've come to the right place. This guide will introduce you to DMARC records, explaining what they are and how they can be used to protect your email domain from spoofing and phishing attacks.
What is a DMARC record?
DMARC stands for which stands for Domain-based Message Authentication, Reporting, and Conformance record is a TXT record that is published in a domain's DNS records. The record specifies how email messages that are sent from the domain should be handled if they fail DMARC authentication. DMARC authentication is a method of verifying that an email message was actually sent from the domain that it claims to be from.
If a message fails DMARC authentication, it means that the message did not come from the domain that it claims to be from. This can happen if the message was spoofed, or if the message was sent using a third-party email service that does not support DMARC authentication.
Why use DMARC for email?
Email spoofing is a serious email security issue because it allows cybercriminals to impersonate legitimate senders and fool recipients into disclosing sensitive information.
DMARC addresses these concerns by providing a mechanism for email senders to authenticate their emails with recipients. This authentication can help to ensure that emails are not spoofed, and it can also help recipients to better identify legitimate emails.
In addition, DMARC can help to protect recipients from phishing attacks. By verifying the authenticity of emails, DMARC can help to prevent recipients from disclosing sensitive information to cybercriminals.
How does it work?
DMARC is used together with SPF and DKIM to authenticate an email. SPF checks that the email is coming from the domain it claims to be coming from. DKIM checks that an email has not been tampered with in transit. DMARC checks that the email has actually been authenticated by SPF or DKIM.
If an email fails any of these checks, it is more likely to be an attempt at phishing or spamming. DMARC checks the email headers to see if the email has been authenticated. DMARC can also be configured to send a report to the domain owner if an email fails authentication. This report can be used to help improve the domain's authentication.
When a message also fails DMARC authentication, the receiving email server can take different actions, depending on the settings specified in the DMARC record. The most common action is to simply delete the message, but the receiving server can also choose to quarantine the message or forward it to the account owner for further review.
DMARC records are a valuable tool for combating email spoofing and phishing attacks. By publishing a DMARC record, you can help to ensure that messages purporting to be from your domain are actually from your domain and that any messages that fail DMARC authentication are properly dealt with.
What are the benefits of DMARC?
DMARC can help to reduce the amount of phishing and spam emails that are sent to users. This can help to protect users from being scammed or tricked into clicking on malicious links. It can also help to improve the deliverability and domain reputation of legitimate emails. This is because DMARC can help to ensure that emails from a domain are properly authenticated.
DMARC can also help to protect the reputation of a domain. This is because DMARC can help to ensure that only emails that are properly authenticated are sent from a domain. This can help to reduce the chances of a domain being marked as spam.
How DMARC domain alignment work
DMARC domain alignment is the process of verifying that the domain in the “From:” header of an email is the same as the domain in the “d=” tag of the DKIM signature. This alignment allows DMARC to more accurately determine whether or not an email is spoofed.
The “d=” tag of the DKIM signature contains the domain name that was used to sign the email. The “From:” header of the email contains the domain name that the email is supposedly from. If these two domain names match, it means that the email has passed domain alignment and is more likely to be legitimate.
If the two domain names do not match, it means that the email has failed domain alignment and is more likely to be spoofed. DMARC can then take appropriate action, such as blocking the email or sending it to the spam folder.
How does DMARC validation work?
DMARC validation works by checking the alignment of the SPF and DKIM policies for a given email message. If both policies are aligned, the message is considered to be valid. If either policy is not aligned, the message is considered to be invalid.
DMARC validation mostly comes from your mail servers. You can test if your mail servers are configured correctly by sending an email to Google Mail (gm…@google.com) and checking if it arrives in your inbox.
The details of the DMARC report can be found in the body of the email message with the subject “Mail Delivery System”. From here, you can see if the email was received successfully or not.
If you get a warning that your message has been blocked, it means that DMARC has not been set up correctly. If you get a warning that your message has been delivered, it means that DMARC has been set up correctly.
Once you have verified that DMARC is working correctly, you can add your domain to the DMARC policy.
When you add your domain to the DMARC policy, you will need to specify a subdomain. The subdomain is the part of the domain that you want to protect with DMARC.
For example, if your domain is example.com, you would specify the subdomain as “www”.
Once you have added your domain to the DMARC policy, you will need to add a TXT record to your DNS settings. The TXT record contains the DMARC policy for your domain.
How to implement a DMARC record
There are a few steps to implementing a DMARC record:
1. Identify the email services that will be sending emails on behalf of your domain. This is very important, as you will need to specify these in your DMARC record.
To identify which services send on behalf of your domain, log in to your email provider and check the settings for your account. You may need to ask your email provider for help if you can’t find the settings yourself.
2. Configure each email service to align its DKIM signature with your domain. Without this alignment, DMARC will not work correctly. If you’re not sure how to set up DKIM, contact your email services provider or domain registrar.
3. Configure each email service to align its SPF record with your domain. Also, without this alignment, DMARC will not work promptly. SPF and DKIM are two authentication methods that can help prevent your own emails from being marked as spam. You will need to set up SPF and DKIM for your domain before you can create a DMARC record.
4. Publish a DMARC record in the DNS of your domain. This record specifies what happens when a message fails DMARC validation. After you have generated your DMARC record, you will need to add it to your DNS. This will tell email servers what to do with emails that fail DMARC authentication.
5. Monitor your DMARC reports to see how your DMARC record is working. Once you have added your DMARC record to your DNS, you will start receiving DMARC reports. These reports will tell you how many of your emails are passing or failing DMARC authentication.
You can use a service like DMARC Analyzer to do this. Then ensure to adjust your DMARC record as needed based on the results of your monitoring. Monitoring these reports is important, as it will help you determine if your DMARC record is working as intended. It will also help you troubleshoot any issues that may arise.
Note: The DMARC record must be published as a TXT record in the DNS of your domain.
What are the drawbacks of DMARC?
One drawback of DMARC is that it can be difficult to configure. This is because DMARC checks the email headers to see if the email has been authenticated. This can be difficult to do if a domain does not have SPF or DKIM configured correctly.
Another drawback of DMARC is that it can block legitimate emails. This is because DMARC checks the email headers to see if the email has been authenticated. If an email has not been authenticated, it is more likely to be an attempt at phishing or spamming. This can cause legitimate emails to be blocked.
Finally, DMARC can be resource intensive. This is because DMARC checks the email headers to see if the email has been authenticated. This can be resource intensive for email servers.
How is DMARC related to SPF, DKIM, or other standards?
DMARC is related to SPF, DKIM, and other standards in that it is designed to work with them to help ensure the security and authenticity of email messages. DMARC builds on the authentication provided by SPF and DKIM by adding a mechanism for receiving feedback about messages that fail authentication checks and specifying how such messages should be handled.
SPF enables senders to specify which IP addresses are authorized to send emails on their behalf. DKIM uses cryptographic signatures to verify that an email message was not modified in transit. DMARC builds on these existing mechanisms by specifying how recipients should handle email that fails SPF or DKIM authentication.
Now you know what a DMARC record is and how it works. DMARC is a great way to improve your email deliverability and protect your brand from phishing attacks. By aligning your SPF and DKIM records with your DMARC policy, you can ensure that your emails are more likely to reach the inbox and that your brand is less likely to be spoofed.