7 Common DMARC Issues and How to Fix Them?
Tags: devops, discuss, beginners, security
Published: 2023-04-13 12:15:17

Introduction
As more and more organizations adopt DMARC, it’s crucial to be aware of the common issues that can arise during its implementation. DMARC helps prevent email spoofing and phishing attacks by verifying that an email message actually comes from the domain it claims to come from. Despite the benefits of DMARC, domain owners can still experience common issues when implementing it. In this article, we will discuss seven common DMARC issues and provide solutions to fix them. By addressing these issues, domain owners can improve their email deliverability and security, and ensure that their emails are reliably delivered to their intended recipients.

DMARC Issuses

1. DMARC Policy Not Set to Reject
One of the most common issues with DMARC implementation is when the DMARC policy is not set to “reject.” This defeats the purpose of DMARC, which is to prevent unauthorized emails from being delivered, even if DMARC authentication fails. To fix this issue, you need to update your DMARC policy to “reject.”

To set your DMARC policy to “reject,” add the following line to your DMARC record: “v=DMARC1; p=reject;” The “p” tag in the DMARC record specifies the policy action to be taken if DMARC authentication fails. The value “reject” tells the recipient’s email provider to reject any email that fails DMARC authentication.

However, it’s important to review your email authentication methods carefully before setting your DMARC policy to “reject” to ensure that legitimate emails won’t be mistakenly rejected. Regularly monitoring your DMARC reports is also essential to ensure that legitimate emails are not being rejected. By setting your DMARC policy to “reject” and regularly monitoring your DMARC reports, you can ensure that your email authentication methods are effective in preventing unauthorized emails from being delivered.

2. SPF Records Not Set Up Correctly
Another common issue with DMARC implementation is when SPF (Sender Policy Framework) records are not set up correctly. SPF records play a crucial role in authenticating email senders and preventing email spoofing. If SPF records are not set up correctly, it can lead to unauthorized emails being delivered to recipients. To resolve this issue, you need to review and update your SPF records to ensure that they are set up correctly. This involves adding the IP addresses of your authorized email servers to your SPF record so that when an email is received, the recipient’s email provider can check the SPF record to verify that the email is being sent from an authorized server. If the email is sent from an unauthorized server, it will fail SPF authentication and be marked as spam or rejected.

To set up your SPF records correctly, you need to add the following line to your DNS records: “v=spf1 include:example.com ~all” Here, “example.com” should be replaced with your organization’s domain name. This line tells the recipient’s email provider to accept any email that is sent from an IP address authorized by the domain in the “From” field of the email.

It’s important to note that setting up SPF records can be complicated. It’s advisable to seek the assistance of an email authentication expert or your email service provider to ensure that your SPF records are set up correctly.

3. DKIM Signing Not Configured Correctly
DKIM (DomainKeys Identified Mail) is an email authentication method used to prevent spoofing by adding a digital signature to an email message that can be verified by the recipient’s email provider. If DKIM signing is not configured correctly, unauthorized emails may be delivered to recipients. To fix this issue, review and update DKIM signing configuration to generate a unique cryptographic key for your domain that is used to sign outgoing emails. The recipient’s email provider can then use this key to verify that the email was sent by an authorized sender and that the message has not been tampered with.

To configure DKIM signing, generate a DKIM key pair and publish the public key as a DNS record for your domain. Configure your email server or email service provider to sign outgoing emails with your private DKIM key. You can generate DKIM key from simpledmarc’s [DKIM Generator](www.simpledmarc.com/dkim-generator.php).

Note that DKIM signing can be complex, so it’s recommended to consult with an email authentication expert or email service provider to ensure proper configuration. By ensuring correct configuration, you can improve email domain deliverability and reputation and prevent unauthorized emails from being delivered.

4. DMARC Record Not Published
To ensure the security of your email domain, you need to authenticate your emails using DMARC (Domain-based Message Authentication, Reporting, and Conformance). DMARC helps prevent email spoofing and ensures that emails sent from your domain are authentic.

However, if you haven’t published a DMARC record, then you’re not using DMARC authentication. DMARC records contain information about your DMARC policy and are published in the DNS (Domain Name System).

To publish a DMARC record, you can add a TXT record to your DNS zone file. The DMARC record should specify how receiving email servers should handle emails that fail SPF and/or DKIM checks. It should also include a policy statement that specifies whether failing emails should be rejected or quarantined, as well as a reporting email address where you can receive DMARC reports.

By publishing a DMARC record for your domain, you can improve the deliverability and reputation of your emails, as well as prevent unauthorized emails from being delivered. However, it’s important to note that publishing a DMARC record can take time to propagate through DNS, so it may take several hours or even days before your DMARC policy is fully effective.

If you want to simplify the process of publishing DMARC records, you can sign up for [SimpleDMARC](www.simpledmarc.com), where you’ll get all the assistance you need for completing and authenticating the DMARC records.

5. DMARC Record Syntax Errors
To authenticate emails from your domain, you need to publish DMARC records in a specific format. Any syntax errors in your DMARC record can prevent email receivers from properly interpreting the record, leading to delivery issues and damaging your domain’s reputation. To fix this issue, you should review and correct any syntax errors in your DMARC record.

Your DMARC record should follow a specific format and be published in the DNS record for your domain. It should specify the version, policy, reporting email address, and subdomain policy (if applicable). You can use a [DMARC checker](www.simpledmarc.com/dmarc-checker.php) tool to verify your record and provide feedback on any syntax errors. Common syntax errors include missing semicolons, incorrect values, and misspelled words.

It is crucial to ensure that your DMARC record is free of syntax errors to prevent email authentication issues and maintain your domain’s reputation.

6. Misconfigured DMARC Aggregate Reports
DMARC aggregate reports provide information about how your emails are being authenticated and delivered. If the DMARC aggregate reports are misconfigured, then you may not receive the information that you need to properly manage your DMARC policy. To fix this issue, you need to review and update your DMARC aggregate report configuration.

First, you need to ensure that your DMARC record includes the “rua” tag, which specifies the email address where aggregate reports will be sent. For example, your DMARC record might include the following rua tag:

“_dmarc.example.com. IN TXT “v=DMARC1; p=none; rua=mailto:dmarc_reports@example.com; sp=none;”

In this example, “example.com” should be replaced with your own domain name, and “dmarc_reports@example.com” should be replaced with the email address where you want to receive aggregate reports.

Once you have ensured that your DMARC record includes the rua tag with the correct email address, you need to monitor your email inbox to ensure that you are receiving the aggregate reports. If you are not receiving the reports, you may need to check your email spam folder, or contact your email provider to ensure that the reports are not being blocked.

7. Failure to Monitor DMARC Reports
Finally, the most common DMARC issues is when you do not monitor your DMARC reports. DMARC reports provide important information about how your emails are being authenticated and delivered. If you are not monitoring your DMARC reports, then you may not be aware of issues that need to be addressed. To fix this issue, you need to set up a system to monitor your DMARC reports regularly.

Here are some steps you can take to ensure that you are properly monitoring your DMARC reports:

Set up automated DMARC reports: Many email providers offer automated DMARC reports that can be sent directly to your inbox on a regular basis. By setting up these reports, you can ensure that you are regularly receiving information on email authentication and delivery for your domain.

Review DMARC reports regularly: Once you have set up your DMARC reports, it is important to regularly review them to identify potential issues. Look for any emails that have failed authentication checks, as well as any unauthorized sources of email traffic.

In conclusion, DMARC is an important email authentication method that helps prevent unauthorized emails from being delivered to your recipients. However, as with any technology, there are common issues that can arise during its implementation. By being aware of these issues and taking steps to fix them, you can ensure that your DMARC implementation is successful.