22 July 2026 · DMARC Engine · 44 min read
The Alignment Conundrum: Third-Party Senders and DMARC
When implementing DMARC, one of the most significant challenges organisations face is achieving alignment with third-party senders. Alignment, in this context, refers to ensuring that the domain in the From header of an email matches the domain authenticated by SPF or DKIM. This is crucial because DMARC relies on this alignment to determine the authenticity of an email. In a hosted or managed setup, such as the one we operate at DMARC Engine, we often see customers struggling to optimise their DMARC configurations for third-party senders.
The problem arises because many third-party senders, such as marketing automation platforms or customer support software, often send emails on behalf of the organisation but may not fully align with the organisation's domain. For instance, a marketing email sent by a third-party service might have a From header with the organisation's domain (e.g., example.com), but the email is actually sent from the third-party's domain (e.g., mailer.example.net). If the SPF or DKIM records for example.com do not include mailer.example.net, DMARC will flag this email as not aligned, potentially leading to delivery issues.
To illustrate this, consider a scenario where example.com has a DMARC record set to p=quarantine and an SPF record that includes only the organisation's own mail servers:
TXT example.com. IN TXT "v=spf1 ip4:192.0.2.1 ip4:192.0.2.2 -all"
TXT _dmarc.example.com. IN TXT "v=DMARC1; p=quarantine; pct=100; rua=mailto:aggrep@example.com; ruf=mailto:forensics@example.com; fo=1"In this case, if a third-party sender like mailer.example.net sends an email with example.com in the From header but is not included in the SPF record, the email will fail DMARC alignment. The organisation might then see this issue reflected in their aggregate reports, such as:
<feedback>
<report_metadata>
<org_name>example.com</org_name>
<email>aggrep@example.com</email>
<extra_contact_info>https://example.com/dmarc</extra_contact_info>
<report_id>example.com.1234567890</report_id>
<date_range>
<begin>2023-01-01T00:00:00Z</begin>
<end>2023-01-01T23:59:59Z</end>
</date_range>
</report_metadata>
<policy_published>
<domain>example.com</domain>
<adkim>r</adkim>
<aspf>r</aspf>
<p>quarantine</p>
<sp>none</sp>
<pct>100</pct>
</policy_published>
<record>
<row>
<source_ip>198.51.100.1</source_ip>
<count>10</count>
<policy_evaluated>
<disposition>quarantine</disposition>
<dkim>none</dkim>
<spf>fail</spf>
</policy_evaluated>
</row>
</record>
</feedback>This report indicates that emails from 198.51.100.1 (the IP of mailer.example.net) failed SPF checks, leading to a quarantine disposition due to the DMARC policy.
To resolve alignment issues with third-party senders, organisations have a few options. They can work with the third-party sender to ensure that the sender's domain is included in the organisation's SPF record or that the sender implements DKIM signing with a selector that aligns with the organisation's domain. Alternatively, organisations might consider relaxing their DMARC policy to p=none while they work on resolving alignment issues, though this should be done cautiously to avoid reducing the effectiveness of DMARC in preventing phishing attacks.
In a managed setup, we often guide customers through this process, helping them identify third-party senders, update their SPF and DKIM configurations as necessary, and monitor their DMARC reports to ensure that alignment issues are resolved without compromising email deliverability. This involves a careful balancing act, as overly restrictive DMARC policies can lead to legitimate emails being blocked, while policies that are too permissive may not effectively prevent spoofing. By carefully evaluating the trade-offs and working closely with third-party senders, organisations can optimise their DMARC configurations to achieve the best possible balance between security and deliverability.
Understanding the Impact of Non-Alignment on Deliverability
When dealing with third-party senders, non-alignment issues can have a significant impact on deliverability, and it is crucial to understand the implications of such issues. In a hosted or managed DMARC setup, such as the one we operate at DMARC Engine, we often see customers struggling to optimise their DMARC configuration to accommodate legitimate third-party senders. Non-alignment occurs when the domain in the From header does not match the domain in the SPF or DKIM record, which can lead to failed DMARC checks and, subsequently, reduced deliverability.
For instance, consider a company like Example Ltd, which uses a third-party marketing platform to send newsletters. The marketing platform may use its own domain, marketing-platform.com, to send emails on behalf of Example Ltd, resulting in a From header with the domain example.com but an SPF record that includes marketing-platform.com. This scenario can cause non-alignment issues, as the domain in the From header does not match the domain in the SPF record.
example.com. IN TXT "v=spf1 include:marketing-platform.com -all"In this case, the SPF record for example.com includes the domain marketing-platform.com, but the From header domain is example.com, which does not match the domain in the SPF record. This non-alignment issue can cause failed DMARC checks, leading to reduced deliverability.
To mitigate this issue, it is essential to ensure that the third-party sender is configured to use a domain that aligns with the domain in the From header. One approach is to use a subdomain, such as marketing.example.com, which can be used in the From header and also included in the SPF record.
marketing.example.com. IN TXT "v=spf1 ip4:192.0.2.1 -all"
example.com. IN TXT "v=spf1 include:marketing.example.com -all"By using a subdomain and including it in the SPF record, the domain in the From header can be aligned with the domain in the SPF record, resolving the non-alignment issue.
However, in some cases, using a subdomain may not be feasible, and alternative solutions must be explored. For instance, some third-party senders may not support using a subdomain or may have technical limitations that prevent them from using a custom domain. In such scenarios, it may be necessary to relax the alignment requirement for legitimate third-party senders. This can be achieved by using the relaxed alignment mode in the DMARC record, which allows for a more flexible alignment check.
example.com. IN TXT "v=DMARC1; p=none; pct=100; rua=mailto:aggregatereports@example.com; aspf=r; adkim=r"In this example, the DMARC record uses the relaxed alignment mode for both SPF and DKIM checks, allowing for a more flexible alignment check. However, it is crucial to note that relaxing the alignment requirement can increase the risk of spoofing attacks, as it allows for more flexibility in the alignment check.
In a hosted or managed DMARC setup, such as the one we operate at DMARC Engine, we can help customers optimise their DMARC configuration to accommodate legitimate third-party senders while minimising the risk of spoofing attacks. By analysing aggregate reports and identifying non-alignment issues, we can work with customers to implement solutions that ensure proper alignment and maintain deliverability. Our experience has shown that a careful analysis of the aggregate reports and a thorough understanding of the third-party sender landscape are essential in resolving non-alignment issues and optimising DMARC configuration.
In addition to using subdomains and relaxing alignment requirements, another approach to resolving non-alignment issues is to use DKIM signing. By using DKIM signing, the third-party sender can sign the email with a domain that aligns with the domain in the From header, resolving the non-alignment issue.
default._domainkey.example.com. IN TXT "v=DKIM1; k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC+yt2wWjwJqH7Xh6Ytl4n7zq4Rj6K6w1K3n9r0k6n9r0k6n9r0k6n9r0k6n9r0k6n"In this example, the DKIM record for example.com includes the public key used for signing, which can be used by the third-party sender to sign the email. By using DKIM signing, the domain in the From header can be aligned with the domain in the DKIM record, resolving the non-alignment issue.
In short, non-alignment issues can have a significant impact on deliverability, and it is crucial to understand the implications of such issues. By using subdomains, relaxing alignment requirements, and using DKIM signing, customers can resolve non-alignment issues and maintain deliverability. As a hosted or managed DMARC setup, we can help customers optimise their DMARC configuration to accommodate legitimate third-party senders while minimising the risk of spoofing attacks. Our experience has shown that a careful analysis of the aggregate reports and a thorough understanding of the third-party sender landscape are essential in resolving non-alignment issues and optimising DMARC configuration.
Identifying Third-Party Senders: The First Step in Troubleshooting
To effectively troubleshoot DMARC alignment issues with third-party senders, it is crucial to first identify these senders. This step is often overlooked, yet it is the foundation upon which all subsequent troubleshooting efforts are built. In a hosted or managed DMARC setup, such as the one we operate at DMARC Engine, we frequently encounter customers who are unaware of the extent of their third-party sender ecosystem.
Third-party senders can include anyone from marketing automation platforms to customer support ticketing systems, and even internal tools that send emails on behalf of the organisation. For instance, a company might use Mailchimp for newsletters, Zendesk for support emails, and an internal application for password reset emails. Each of these senders must be identified and assessed for DMARC alignment.
When identifying third-party senders, it is essential to consider both the organisational and technical aspects. From an organisational standpoint, engaging with various departments (such as marketing, customer support, and IT) can help compile a comprehensive list of third-party senders. Technically, analysing email headers and aggregate reports can provide valuable insights. For example, examining the Return-Path or Sender headers in email messages can reveal the domain or IP address of the sender, which may indicate a third-party service.
Example of an email header showing a third-party sender:
Return-Path: <bounce-mailchimp@example.com>In this example, the presence of mailchimp in the Return-Path header suggests that Mailchimp is being used as a third-party sender. Similarly, aggregate reports (RUA) received as part of DMARC implementation can list sources of email that are failing DMARC checks, often highlighting third-party senders that need attention.
Example snippet from an aggregate report:
<record>
<row>
<source_ip>192.0.2.1</source_ip>
<count>10</count>
<policy_evaluated>
<disposition>none</disposition>
<dkim>fail</dkim>
<spf>fail</spf>
</policy_evaluated>
</row>
<identifiers>
<header_from>example.net</header_from>
</identifiers>
<auth_results>
<dkim>
<domain>mailchimp.net</domain>
<result>fail</result>
</dkim>
<spf>
<domain>example.net</domain>
<result>fail</result>
</spf>
</auth_results>
</record>This report snippet indicates that emails claiming to be from example.net are being sent from 192.0.2.1 (which might be a Mailchimp IP) and are failing both DKIM and SPF checks, suggesting a potential alignment issue with a third-party sender.
In a managed setup, tools and processes are in place to automate the collection and analysis of such data, making it easier to identify and manage third-party senders. However, even with automation, human oversight is necessary to interpret the data correctly and make informed decisions about how to proceed with troubleshooting and potentially relaxing DMARC policies for legitimate third-party senders.
Identifying all third-party senders is an ongoing process that requires regular audits and updates, as the ecosystem of senders can change over time. New services might be adopted, or existing ones might change their sending practices, affecting DMARC alignment. Therefore, maintaining a dynamic inventory of third-party senders and monitoring their DMARC compliance is central to optimising email deliverability and preventing unnecessary blocking of legitimate emails.
Analysing Aggregate Reports for DMARC Alignment Issues
Analysing aggregate reports is a crucial step in identifying DMARC alignment issues with third-party senders. These reports, typically sent to the email address specified in the DMARC record, contain valuable information about the authentication results of emails sent from your domain. As a hosted DMARC provider, we organise these reports in a colour-coded dashboard to help our customers quickly identify potential issues.
When examining aggregate reports, it is essential to focus on the authentication results, specifically the DKIM and SPF alignment. A common issue we see is that many customers do not realise that a single misaligned IP address can cause a significant portion of their emails to fail DMARC authentication. For instance, if a third-party sender is using a mail server with a different domain or IP address, it may not align with your DMARC record, resulting in authentication failures.
To illustrate this, let's consider an example of an aggregate report snippet:
<feedback>
<report_metadata>
<org_name>example.com</org_name>
<email>example@example.com</email>
<extra_contact_info>https://example.com/dmarc</extra_contact_info>
<report_id>1234567890</report_id>
<date_range>
<begin>2022-01-01T00:00:00Z</begin>
<end>2022-01-07T23:59:59Z</end>
</date_range>
</report_metadata>
<policy_published>
<domain>example.com</domain>
<adkim>r</adkim>
<aspf>r</aspf>
<p>none</p>
<sp>none</sp>
<pct>100</pct>
</policy_published>
<record>
<row>
<source_ip>192.0.2.1</source_ip>
<count>100</count>
<policy_evaluated>
<disposition>none</disposition>
<dkim>fail</dkim>
<spf>fail</spf>
</policy_evaluated>
</row>
</record>
</feedback>In this example, the report indicates that 100 emails were sent from the IP address 192.0.2.1, but both DKIM and SPF authentication failed. This suggests a potential alignment issue with the third-party sender using this IP address.
To address this issue, we recommend that our customers take a closer look at their third-party senders and verify that they are using aligned mail servers or IP addresses. In some cases, it may be necessary to relax the alignment requirements or add additional IP addresses to the DMARC record. However, this should be done with caution, as it may compromise the security of the domain.
In a hosted or managed setup, we can help customers optimise their DMARC records to ensure proper alignment with third-party senders. Our system can automatically detect misaligned IP addresses and provide recommendations for updating the DMARC record. We also offer a feature to track changes to the DMARC record over time, which helps customers monitor the effectiveness of their alignment adjustments.
Another common issue we encounter is that customers often overlook the importance of monitoring their aggregate reports regularly. These reports can provide valuable insights into authentication issues and help identify potential problems before they become major deliverability issues. We recommend that our customers check their aggregate reports at least once a week, and ideally, set up automated alerts for any significant changes in authentication results.
In addition to monitoring aggregate reports, it is also crucial to analyse the authentication results for each third-party sender. This can help identify specific senders that are causing alignment issues and allow for targeted adjustments to the DMARC record. For example, if a customer is using a marketing automation platform that is sending emails on their behalf, they may need to add the platform's IP addresses to their DMARC record to ensure proper alignment.
To make this process easier, we provide our customers with a detailed breakdown of authentication results for each third-party sender. This includes information on the sender's IP address, authentication method, and alignment status. By analysing this data, customers can quickly identify potential issues and make adjustments to their DMARC record to optimise deliverability.
In short, analysing aggregate reports is a critical step in identifying and addressing DMARC alignment issues with third-party senders. By monitoring these reports regularly and analysing authentication results for each sender, customers can ensure proper alignment and optimise their deliverability. As a hosted DMARC provider, we can help customers streamline this process and provide recommendations for updating their DMARC records to ensure the best possible deliverability.
One final point to consider is that DMARC alignment issues can be complex and require a deep understanding of email authentication protocols. If you are not familiar with these protocols, it may be helpful to work with a hosted or managed DMARC provider that can offer expert guidance and support. Our team of engineers has extensive experience in troubleshooting DMARC alignment issues and can help customers navigate even the most complex problems. By working together, we can help ensure that your emails are delivered safely and securely to your customers' inboxes.
For instance, we had a customer who was experiencing deliverability issues with their marketing emails. After analysing their aggregate reports, we discovered that one of their third-party senders was using a misaligned IP address, causing a significant portion of their emails to fail DMARC authentication. We worked with the customer to update their DMARC record and add the sender's IP address to the allowed list. As a result, their deliverability rates improved significantly, and they were able to reach their customers more effectively.
This example highlights the importance of regularly monitoring aggregate reports and analysing authentication results for each third-party sender. By taking a proactive approach to DMARC alignment, customers can ensure that their emails are delivered safely and securely, and avoid potential deliverability issues.
In our experience, the key to successful DMARC alignment is to strike a balance between security and deliverability. While it is essential to ensure that your DMARC record is secure and aligned with your third-party senders, it is also crucial to avoid overly restrictive policies that may block legitimate emails. By working with a hosted or managed DMARC provider, customers can ensure that their DMARC record is optimised for both security and deliverability, and that they are getting the best possible results from their email marketing campaigns.
To achieve this balance, we recommend that our customers take a step-by-step approach to DMARC alignment. This involves identifying all third-party senders, verifying their IP addresses and authentication methods, and updating the DMARC record accordingly. We also recommend that customers monitor their aggregate reports regularly and analyse authentication results for each sender to ensure that their DMARC record is working effectively.
By following these steps and working with a hosted or managed DMARC provider, customers can ensure that their emails are delivered safely and securely, and that they are getting
SPF Alignment: Practical Considerations and Examples
When dealing with third-party senders, SPF alignment can be a complex issue, as it requires the sender's domain to be aligned with the domain used in the From header of the email. In a hosted or managed setup, such as the one we operate at DMARC Engine, we often see customers struggling to achieve SPF alignment due to the sheer number of third-party senders they work with. For instance, a customer may use a marketing automation platform, a CRM system, and a customer support tool, all of which send emails on their behalf.
To achieve SPF alignment, the customer needs to ensure that each of these third-party senders is included in their SPF record. This can be a daunting task, especially if the customer has a large number of senders. We recommend using a tool to help manage SPF records, such as our own SPF manager, which allows customers to easily add or remove senders from their record.
A typical SPF record might look like this:
v=spf1 include:_spf.example.com include:sendgrid.net include:mailchimp.com -allIn this example, the domain is including the SPF records of _spf.example.com, sendgrid.net, and mailchimp.com. This allows emails sent from these domains to be authenticated by the customer's SPF record. However, if a third-party sender is not included in the SPF record, emails sent from that sender will fail SPF authentication, leading to DMARC alignment issues.
One common issue we see is customers trying to include too many senders in their SPF record. While it may seem like a good idea to include every possible sender, this can actually lead to problems. For one, it can make the SPF record too large, which can cause issues with DNS lookup limits. Also, including too many senders can increase the risk of SPF record abuse, where an attacker tries to exploit a weak SPF record to send spam emails.
To avoid these issues, we recommend taking a more targeted approach to SPF alignment. Instead of trying to include every possible sender, customers should focus on identifying their most critical senders and ensuring those are included in the SPF record. For less critical senders, customers can use other authentication methods, such as DKIM, to achieve DMARC alignment.
Another consideration is the use of include statements in SPF records. While include statements can be useful for including the SPF records of third-party senders, they can also lead to problems if not used carefully. For example, if a third-party sender has a weak SPF record, including that record in the customer's SPF record can compromise the security of the customer's domain.
To mitigate this risk, we recommend using include statements sparingly and only with trusted senders. Customers should also regularly review their SPF record to ensure it is up to date and secure.
In terms of specific examples, we have seen cases where customers have tried to use include statements to include the SPF records of multiple senders, only to find that one of the senders has a weak SPF record that compromises the security of the customer's domain. For instance, a customer might try to include the SPF records of both sendgrid.net and mailchimp.com in their SPF record, like this:
v=spf1 include:sendgrid.net include:mailchimp.com -allHowever, if mailchimp.com has a weak SPF record, this could compromise the security of the customer's domain. To avoid this issue, the customer could use a more targeted approach, such as including only the specific IP addresses used by sendgrid.net and mailchimp.com, like this:
v=spf1 ip4:192.0.2.1 ip4:198.51.100.1 -allThis approach ensures that only emails sent from the specified IP addresses are authenticated by the customer's SPF record, reducing the risk of SPF record abuse.
In a hosted or managed setup, we can help customers manage their SPF records and ensure they are secure and up to date. Our system allows customers to easily add or remove senders from their SPF record, and we provide regular security audits to ensure the customer's domain is protected.
Ultimately, achieving SPF alignment with third-party senders requires a careful and targeted approach. By understanding the practical considerations and examples outlined above, customers can ensure their SPF record is secure and effective, and that their emails are properly authenticated and delivered to their intended recipients.
We also recommend that customers use a tool to help monitor their SPF record and detect any potential issues. This can include tools such as our own SPF monitoring system, which provides real-time alerts and notifications if there are any problems with the customer's SPF record.
By taking a proactive and targeted approach to SPF alignment, customers can ensure their emails are properly authenticated and delivered, and that their domain is protected from spam and phishing attacks.
In addition to the technical considerations outlined above, there are also organisational and process-related aspects to consider when implementing SPF alignment. For example, customers should ensure that they have a clear understanding of which third-party senders are sending emails on their behalf, and that they have a process in place for adding or removing senders from their SPF record.
This can involve working closely with the customer's IT and marketing teams to ensure that everyone is aware of the importance of SPF alignment and the steps that need to be taken to achieve it.
By taking a holistic approach to SPF alignment, customers can ensure that their emails are properly authenticated and delivered, and that their domain is protected from spam and phishing attacks.
In terms of best practices, we recommend that customers follow these guidelines when implementing SPF alignment:
* Use a targeted approach to SPF alignment, focusing on the most critical senders and using other authentication methods for less critical senders.
* Use include statements sparingly and only with trusted senders.
* Regularly review the SPF record to ensure it is up to date and secure.
* Use a tool to help monitor the SPF record and detect any potential issues.
* Have a clear understanding of which third-party senders are sending emails on behalf of the customer, and have a process in place for adding or removing senders from the SPF record.
By following these best practices, customers can ensure that their SPF record is secure and effective, and that their emails are properly authenticated and delivered to their intended recipients.
It is also worth noting that SPF alignment is just one aspect of DMARC alignment, and that customers should also consider DKIM alignment and other factors when implementing a DMARC strategy.
By taking a comprehensive approach to DMARC alignment, customers can ensure that their emails are properly authenticated and delivered, and that their domain is protected from spam and phishing attacks.
In our experience, achieving SPF alignment with third-party senders can be a complex and time-consuming process, but it is a critical step in ensuring the security and deliverability of emails.
By following the guidelines and best practices outlined above, customers can ensure that their SPF record is secure and effective, and that their emails are properly authenticated and delivered to their intended recipients.
We also recommend that customers regularly review and update their SPF record to ensure it remains secure and effective over time.
This can involve working closely with the customer's IT and marketing teams to ensure that everyone is aware of the importance of SPF alignment and the
DKIM Alignment: Challenges and Solutions for Third-Party Senders
DKIM alignment can be a complex issue when dealing with third-party senders, as it requires the sender's domain to match the domain in the DKIM signature. In a hosted or managed setup, such as the one we use at DMARC Engine, we often see customers struggling to achieve DKIM alignment with their third-party senders. One of the main challenges is that third-party senders may use their own domain in the DKIM signature, rather than the customer's domain. For example, a customer may use a marketing automation platform like Marketo to send emails, but the DKIM signature may be signed with Marketo's domain (d=marketo.com) rather than the customer's domain (d=customer.com).
To overcome this challenge, we recommend that customers work with their third-party senders to configure DKIM signing with the customer's domain. This can typically be done by generating a new DKIM key pair and providing the public key to the third-party sender. The third-party sender can then use this key pair to sign emails with the customer's domain. We have seen this approach work well with a number of third-party senders, including Mailchimp and Salesforce.
Another challenge with DKIM alignment is that some third-party senders may use a subdomain in the DKIM signature, rather than the customer's main domain. For example, a customer may use a domain like customer.com, but the third-party sender may sign emails with a subdomain like mail.customer.com. In this case, the DKIM signature may not align with the customer's domain, even if the third-party sender is configured to sign with the customer's domain.
To address this issue, we recommend that customers use a wildcard DKIM record, such as:
default._domainkey.customer.com. IN TXT "v=DKIM1; k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC4hxBKnFmi9hgQ7Z3mRc5+6FVc0i6mFmZ3rhKQZeepjszF8kyJypz0ieQ9AKUHh4JZ3UhuCQVcB5PjQshVYj3SSYr4cV7J3r7xW4HzB+oMdGjCp4tHrj5m4Y9Z4FQ9r4T5FQ9r4T5FQ9r4T5FQ9r4T5FQ9r4Tj3SSYr4cV7J3"This allows the customer to use a single DKIM record for all subdomains, which can help to simplify the configuration process and reduce the risk of DKIM alignment issues.
In addition to these technical challenges, there are also some organisational challenges to consider when implementing DKIM alignment with third-party senders. For example, customers may need to work with multiple stakeholders, including the third-party sender, the customer's IT department, and the customer's marketing team, to configure DKIM signing and ensure that it is working correctly. This can be a time-consuming and complex process, especially for larger organisations with many different stakeholders.
To overcome these organisational challenges, we recommend that customers establish a centre of excellence for DMARC and email deliverability, which can provide a single point of contact and expertise for all email deliverability issues. This centre of excellence can work with the customer's stakeholders to configure DKIM signing, troubleshoot issues, and provide training and support to ensure that the customer's email programme is running smoothly and efficiently.
In terms of specific solutions, we have seen a number of different approaches work well for DKIM alignment with third-party senders. One approach is to use a third-party service, such as a managed DKIM service, which can provide a simple and straightforward way to configure DKIM signing and ensure that it is working correctly. Another approach is to use an automated tool, such as a script or a software programme, to configure DKIM signing and troubleshoot issues.
For example, we have worked with a number of customers who use a tool like OpenDKIM to automate the DKIM signing process. This tool can be configured to sign emails with the customer's domain, and can also provide reporting and analytics to help the customer troubleshoot issues and optimise their email programme. We have seen this approach work well for customers who have a large number of third-party senders, or who need to configure DKIM signing for a large number of domains.
In terms of best practices, we recommend that customers follow a number of key principles when implementing DKIM alignment with third-party senders. First, customers should ensure that they have a clear understanding of their email programme and the different stakeholders involved. This includes understanding the different third-party senders that are used, as well as the different domains and subdomains that are involved.
Second, customers should establish a centre of excellence for DMARC and email deliverability, which can provide a single point of contact and expertise for all email deliverability issues. This centre of excellence can work with the customer's stakeholders to configure DKIM signing, troubleshoot issues, and provide training and support to ensure that the customer's email programme is running smoothly and efficiently.
Third, customers should use a simple and straightforward approach to configuring DKIM signing, such as using a third-party service or an automated tool. This can help to reduce the risk of errors and ensure that DKIM signing is working correctly.
Finally, customers should monitor their email programme regularly, using tools like aggregate reports and email analytics, to ensure that DKIM alignment is working correctly and to identify any issues that may need to be addressed. By following these best practices, customers can help to ensure that their email programme is running smoothly and efficiently, and that they are able to achieve DKIM alignment with their third-party senders.
To illustrate the importance of monitoring and troubleshooting, let's consider an example of a customer who implemented DKIM alignment with a third-party sender, but failed to monitor their email programme regularly. In this case, the customer configured DKIM signing with the third-party sender, but did not check to ensure that it was working correctly. As a result, the customer's emails were not being signed with the correct domain, which caused deliverability issues and resulted in a significant decrease in email engagement.
To troubleshoot this issue, the customer needed to review their aggregate reports and email analytics to identify the problem. They also needed to work with the third-party sender to reconfigure DKIM signing and ensure that it was working correctly. This process took several days and required significant resources, but ultimately helped the customer to resolve the issue and improve their email deliverability.
In contrast, customers who monitor their email programme regularly can often identify and resolve issues quickly, which can help to minimise the impact on their email programme and ensure that their emails are being delivered to the inbox. For example, we have worked with a number of customers who use automated tools to monitor their email programme and identify issues in real-time. These customers are often able to resolve issues quickly, which can help to improve their email deliverability and reduce the risk of errors.
In terms of trade-offs, there are a number of different considerations that customers should be aware of when implementing DKIM alignment with third-party senders. One key trade-off is between the level of control and flexibility that the customer has over the DKIM signing process, and the level of complexity and risk that is involved. For example, customers who use a third-party service to configure DKIM signing may have less control over the process, but may also have less risk and complexity.
Another key trade-off is between the cost and resources required to implement DKIM alignment, and the
From Theory to Practice: Real-World Examples of DMARC Alignment
When dealing with DMARC alignment issues, theory can only take you so far. In practice, the colour of real-world scenarios often reveals nuances that can make or break your email deliverability. At DMARC Engine, we have seen our fair share of alignment conundrums, and it is crucial to understand how different third-party senders interact with your DMARC setup.
Consider a scenario where a customer uses a third-party marketing platform, such as Marketo, to send emails. The customer's domain is example.com, and they have set up DMARC with a policy of quarantine. However, Marketo uses its own domain, marketo.com, to send emails on behalf of example.com. This is where alignment issues come into play.
To align with DMARC, Marketo needs to use a subdomain of example.com, such as mkt.example.com, and set up SPF and DKIM records accordingly. Here is an example of what the SPF record for mkt.example.com might look like:
mkt.example.com. IN TXT "v=spf1 include:marketo.com -all"In this example, the include directive tells the SPF checker to include the IP addresses specified in the marketo.com SPF record. This allows Marketo to send emails on behalf of example.com while maintaining SPF alignment.
DKIM alignment is also crucial in this scenario. Marketo needs to generate a DKIM signature using a selector, such as s1, and a domain, mkt.example.com. The resulting DKIM signature would be verified by the receiving mail server using the public key published in the DNS record for mkt.example.com. Here is an example of what the DKIM record for mkt.example.com might look like:
s1._domainkey.mkt.example.com. IN TXT "k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC+ypwbq3a5cK3N4/8u8P4H4M0xKzKKw7Kl9T8j7rOyD6K2d0k0eU1+JYH6r4e0k0eU1+JYH6r4e"In a hosted or managed setup, such as DMARC Engine, we handle the complexity of setting up and managing these records for our customers. However, it is essential for customers to understand the underlying mechanics to troubleshoot issues effectively.
Another common scenario we encounter is when a customer uses a third-party email service provider, such as Sendgrid, to send transactional emails. In this case, Sendgrid uses its own IP addresses to send emails, which can cause SPF alignment issues. To resolve this, Sendgrid provides a subdomain, such as sendgrid.net, which customers can use to set up SPF and DKIM records. Here is an example of what the SPF record for sendgrid.net might look like:
sendgrid.net. IN TXT "v=spf1 ip4:167.89.106.0/23 ip4:168.245.24.0/23 ip4:169.38.0.0/16 -all"In this example, the ip4 directive specifies the IP addresses used by Sendgrid to send emails. By including this record in their SPF setup, customers can maintain SPF alignment when using Sendgrid to send transactional emails.
When it comes to DKIM alignment, Sendgrid provides a DKIM selector, such as sg, which customers can use to generate a DKIM signature. The resulting DKIM signature would be verified by the receiving mail server using the public key published in the DNS record for sendgrid.net. Here is an example of what the DKIM record for sendgrid.net might look like:
sg._domainkey.sendgrid.net. IN TXT "k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC+ypwbq3a5cK3N4/8u8P4H4M0xKzKKw7Kl9T8j7rOyD6K2d0k0eU1+JYH6r4e0k0eU1+JYH6r4e"In our experience, one of the most common mistakes customers make when setting up DMARC alignment is not properly configuring their third-party senders. This can lead to a significant increase in false positives, resulting in legitimate emails being blocked or quarantined. To avoid this, it is crucial to work closely with your third-party senders to ensure they are properly configured to maintain DMARC alignment.
In addition to proper configuration, it is also essential to monitor your DMARC aggregate reports regularly to identify any alignment issues. These reports provide valuable insights into your email ecosystem, allowing you to pinpoint areas where alignment issues may be occurring. By analysing these reports, you can optimise your DMARC setup to improve deliverability and reduce the risk of spoofing.
At DMARC Engine, we provide our customers with detailed aggregate reports, which include information on SPF and DKIM alignment, as well as the IP addresses and domains used by third-party senders. Here is an example of what an aggregate report might look like:
{
"report_metadata": {
"org_name": "example.com",
"email": "dmarc@example.com",
"extra_contact_info": "https://example.com/dmarc",
"report_id": "1234567890",
"date_range": {
"begin": "2022-01-01T00:00:00Z",
"end": "2022-01-07T23:59:59Z"
}
},
"policy_published": {
"domain": "example.com",
"adkim": "r",
"aspf": "r",
"p": "quarantine",
"sp": "quarantine",
"pct": 100
},
"records": [
{
"row": {
"source_ip": "192.0.2.1",
"count": 100,
"policy_evaluated": {
"disposition": "none",
"dkim": "pass",
"spf": "pass"
}
}
},
{
"row": {
"source_ip": "198.51.100.1",
"count": 50,
"policy_evaluated": {
"disposition": "quarantine",
"dkim": "fail",
"spf": "fail"
}
}
}
]
}In this example, the aggregate report shows two records, one with a passing DKIM and SPF alignment, and another with a failing DKIM and SPF alignment. By analysing this report, the customer can identify the source of the alignment issue and take corrective action to maintain DMARC alignment.
In conclusion to this section, real-world examples of DMARC alignment highlight the complexity of email ecosystems and the need for careful configuration and monitoring. By understanding the mechanics of DMARC alignment and working closely with third-party senders, customers can optimise their DMARC setup to improve deliverability and reduce the risk of spoofing. As a hosted or managed setup, DMARC Engine handles the complexity of setting up and managing DMARC records for our customers, but it is essential for customers to understand the underlying mechanics to troubleshoot issues effectively.
Trade-Offs and Decisions: Relaxing Alignment for Legitimate Senders
When dealing with third-party senders, one of the most critical decisions is whether to relax alignment requirements for legitimate senders. This decision is not straightforward, as it involves weighing the benefits of allowing non-aligned mail against the risks of spoofing and phishing attacks. In our experience, hosted DMARC solutions can simplify this process by providing a centralised platform to manage and monitor third-party senders.
Relaxing alignment for legitimate senders can be necessary when a third-party service is unable to align its SPF or DKIM records with the domain owner's domain. For instance, a marketing automation platform may use a shared IP address for multiple customers, making it difficult to set up an SPF record that aligns with each customer's domain. In such cases, relaxing alignment can ensure that legitimate mail is not blocked by DMARC checks.
However, relaxing alignment can also increase the risk of spoofing and phishing attacks. If an attacker is able to send mail from a non-aligned IP address, they may be able to bypass DMARC checks and deliver malicious mail to the recipient's inbox. To mitigate this risk, it is essential to carefully evaluate the legitimacy of each third-party sender and to implement additional security measures, such as monitoring aggregate reports and setting up custom DMARC policies.
One approach to relaxing alignment is to use a custom DMARC policy that allows non-aligned mail from specific IP addresses or domains. For example, a domain owner may set up a DMARC record with a p tag set to none and an sp tag set to quarantine, while also specifying a list of allowed IP addresses or domains in the ip or domain tags. This approach can help to ensure that legitimate mail from third-party senders is not blocked, while still providing some level of protection against spoofing and phishing attacks.
Example DMARC record with custom policy:
v=DMARC1; p=none; sp=quarantine; ip=192.0.2.1; domain=example.netIn this example, the DMARC record specifies a policy of none for the domain owner's domain, while allowing mail from the IP address 192.0.2.1 and the domain example.net. This approach can be useful for third-party senders that are unable to align their SPF or DKIM records with the domain owner's domain.
Another approach is to use a hosted DMARC solution that provides a centralised platform for managing and monitoring third-party senders. These solutions often provide features such as automated IP address and domain allowlisting, custom DMARC policy management, and real-time reporting and analytics. By using a hosted DMARC solution, domain owners can simplify the process of relaxing alignment for legitimate senders, while still maintaining control over their DMARC policies.
In our experience, the key to successfully relaxing alignment for legitimate senders is to carefully evaluate the risks and benefits and to implement additional security measures to mitigate the risks of spoofing and phishing attacks. This may involve monitoring aggregate reports, setting up custom DMARC policies, and using hosted DMARC solutions to simplify the management of third-party senders. By taking a careful and considered approach, domain owners can ensure that their DMARC policies are optimised for both security and deliverability.
It is also worth noting that relaxing alignment can have colour implications for the domain owner's brand. If a domain owner is seen to be allowing non-aligned mail, it may damage their reputation and lead to a loss of customer trust. Therefore, it is essential to carefully consider the potential colour implications of relaxing alignment and to implement measures to mitigate any potential risks.
In terms of optimising DMARC for third-party senders, it is essential to take a long-term view and to consider the potential risks and benefits of relaxing alignment. This may involve implementing a centre of excellence approach, where a team of experts is responsible for managing and monitoring DMARC policies and third-party senders. By taking a proactive and considered approach, domain owners can ensure that their DMARC policies are optimised for both security and deliverability, while also protecting their brand and reputation.
To centre the decision-making process around the needs of the organisation, it is crucial to organise the available data and to analyse the potential risks and benefits of relaxing alignment. This may involve setting up a data-driven framework for evaluating the legitimacy of third-party senders and for monitoring the effectiveness of DMARC policies. By using data to inform decision-making, domain owners can ensure that their DMARC policies are aligned with their organisational goals and objectives.
Ultimately, the decision to relax alignment for legitimate senders is a complex one that requires careful consideration of the potential risks and benefits. By taking a thoughtful and data-driven approach, domain owners can ensure that their DMARC policies are optimised for both security and deliverability, while also protecting their brand and reputation.
Optimising DMARC for Third-Party Senders: Long-Term Strategies
To optimise DMARC for third-party senders, organisations must centre their strategy around a deep understanding of their email ecosystem, including all legitimate senders. This involves implementing a combination of technical and process-oriented solutions to ensure that DMARC alignment is maintained, while also allowing for the flexibility needed to accommodate various third-party sending scenarios.
One key aspect of this strategy is to organise third-party senders into categories based on their sending patterns and requirements. For instance, senders that only send occasional, low-volume emails may not require the same level of scrutiny as those sending high-volume, frequent emails. By categorising senders in this way, organisations can tailor their DMARC strategies to meet the specific needs of each group, thereby optimising their overall email deliverability.
In a hosted or managed setup, such as the one provided by DMARC Engine, this categorisation can be facilitated through the use of customised reporting and analytics tools. These tools enable organisations to gain a detailed understanding of their email sending patterns, including the volume, frequency, and authentication methods used by each sender. With this information, organisations can make informed decisions about how to configure their DMARC settings to achieve the best possible balance between security and deliverability.
Another important consideration for optimising DMARC is the use of subdomains. Many organisations use subdomains to segregate different types of email traffic, such as marketing emails versus transactional emails. However, this can create challenges for DMARC alignment, particularly if the subdomains are not properly configured. To mitigate this risk, organisations should ensure that each subdomain has its own DMARC record, and that these records are regularly monitored and updated to reflect changes in sending patterns.
For example, an organisation might use the subdomain marketing.example.com for all marketing emails, and transactional.example.com for all transactional emails. In this scenario, the DMARC records for each subdomain might look like this:
marketing.example.com. IN TXT "v=DMARC1; p=none; sp=none; adkim=r; aspf=r; fo=1"
transactional.example.com. IN TXT "v=DMARC1; p=quarantine; sp=none; adkim=r; aspf=r; fo=1"As shown in the above example, the DMARC record for the marketing subdomain has a policy of none, indicating that emails from this subdomain should not be blocked or quarantined, even if they fail DMARC authentication. In contrast, the DMARC record for the transactional subdomain has a policy of quarantine, indicating that emails from this subdomain should be quarantined if they fail DMARC authentication. This reflects the different risk profiles associated with marketing versus transactional emails.
In addition to subdomains, organisations should also consider the use of email service providers (ESPs) and other third-party senders. These senders often have their own DMARC records, which can create conflicts with the organisation's own DMARC settings. To resolve these conflicts, organisations should work closely with their ESPs and other third-party senders to ensure that their DMARC records are properly aligned.
One way to achieve this alignment is through the use of SPF and DKIM authentication. By ensuring that all emails sent on behalf of the organisation are authenticated using SPF and DKIM, organisations can help to prevent spoofing and ensure that their emails are delivered to the intended recipients. For example, an organisation might include the following SPF record in their DNS configuration:
example.com. IN TXT "v=spf1 include:_spf.example.net include:_spf.example.io -all"This record indicates that the organisation uses two ESPs, example.net and example.io, and that emails sent from these domains should be included in the organisation's SPF record.
Similarly, organisations can use DKIM to authenticate emails sent on their behalf. This involves generating a public-private key pair, and then publishing the public key in the organisation's DNS configuration. For example:
default._domainkey.example.com. IN TXT "v=DKIM1; k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCqGKukO1De7zhZj6+H0qtjTkVxwTCpvKe4eCZ0FPqri0cb2JZfXJ/DgYSF6vUpwmJG8wVQZKjeGcjDOL5UlsuusFncCzWBQ7RKNUSesmQRMSGkVb1/3j+skZ6UtW+5u09lHNsj6tQ51s1SPrCBkedbNf0Tp0GbMJDyR4e9T04ZZwIDAQAB"This record publishes the public key associated with the organisation's DKIM private key, allowing receivers to verify the authenticity of emails sent on the organisation's behalf.
By implementing these technical and process-oriented solutions, organisations can optimise their DMARC settings for third-party senders, and help to ensure that their emails are delivered to the intended recipients. This requires ongoing monitoring and maintenance, as well as a deep understanding of the organisation's email ecosystem and the various third-party senders involved. However, with the right strategy and tools in place, organisations can achieve a high level of email deliverability, while also maintaining the security and integrity of their email communications.
In a hosted or managed setup, such as the one provided by DMARC Engine, organisations can leverage the expertise and resources of the hosting provider to help optimise their DMARC settings and ensure the best possible email deliverability. This can include access to advanced reporting and analytics tools, as well as expert guidance on DMARC configuration and management. By working closely with the hosting provider, organisations can ensure that their DMARC settings are properly aligned with their email ecosystem, and that their emails are delivered to the intended recipients.
To colour this with a real-world example, consider a large e-commerce organisation that uses multiple third-party senders to send marketing and transactional emails. This organisation might work with DMARC Engine to implement a customised DMARC solution that takes into account the different sending patterns and requirements of each third-party sender. This might involve creating separate DMARC records for each subdomain, as well as implementing SPF and DKIM authentication to ensure that all emails sent on behalf of the organisation are properly authenticated. By taking a proactive and tailored approach to DMARC management, this organisation can help to ensure that its emails are delivered to the intended recipients, while also maintaining the security and integrity of its email communications.
Ultimately, optimising DMARC for third-party senders requires a deep understanding of the organisation's email ecosystem, as well as the various technical and process-oriented solutions available to manage DMARC settings. By leveraging the right tools and expertise, organisations can achieve a high level of email deliverability, while also maintaining the security and integrity of their email communications.
Centre of Excellence: Building a DMARC Troubleshooting Framework
To effectively troubleshoot DMARC alignment issues with third-party senders, it is crucial to establish a centre of excellence that outlines the procedures, tools, and best practices for identifying and resolving these issues. This framework should be tailored to the organisation's specific email ecosystem, taking into account the various third-party senders, email service providers, and internal stakeholders involved.
At the centre of this framework should be a clear understanding of the organisation's email architecture, including all third-party senders, their respective roles, and the authentication protocols they use. For instance, a company may use a marketing automation platform that sends emails on their behalf, while also using a customer support platform that sends emails from a different domain.
In a hosted or managed setup, such as the one we operate at DMARC Engine, this information is readily available and can be easily accessed through our dashboard. However, for organisations managing their DMARC setup in-house, it is essential to maintain an up-to-date inventory of all third-party senders, including their IP addresses, domains, and authentication protocols.
A key component of the troubleshooting framework is the analysis of aggregate reports, which provide valuable insights into DMARC alignment issues. These reports can be overwhelming, especially for large organisations with multiple third-party senders. To optimise the analysis process, it is recommended to use automated tools that can parse the reports, identify alignment issues, and provide actionable recommendations.
For example, the following aggregate report snippet highlights a DMARC alignment issue with a third-party sender:
<record>
<row>
<source_ip>192.0.2.1</source_ip>
<count>10</count>
<policy_evaluated>
<disposition>none</disposition>
<dkim>fail</dkim>
<spf>fail</spf>
</policy_evaluated>
</row>
<identifiers>
<header_from>example.com</header_from>
</identifiers>
</record>In this example, the third-party sender with the IP address 192.0.2.1 is failing both DKIM and SPF alignment, resulting in a DMARC failure. The troubleshooting framework should outline the steps to take in such a scenario, including contacting the third-party sender, verifying their authentication protocols, and updating the organisation's DMARC policy as needed.
Another critical aspect of the framework is the establishment of a colour-coded system to categorise third-party senders based on their alignment status. For instance, senders with a high volume of DMARC failures could be marked as 'red', indicating a high priority for troubleshooting, while senders with occasional failures could be marked as 'amber', indicating a medium priority.
This colour-coded system can be used to optimise the troubleshooting process, ensuring that the most critical issues are addressed first. Also, the framework should outline the procedures for relaxing alignment for legitimate senders, such as using a more permissive DMARC policy or implementing a custom authentication protocol.
To further optimise the framework, it is recommended to establish a centre of excellence team that meets regularly to discuss DMARC alignment issues, share best practices, and review the effectiveness of the troubleshooting procedures. This team should include representatives from various stakeholders, including email operations, security, and compliance.
By building a comprehensive DMARC troubleshooting framework, organisations can effectively identify and resolve alignment issues with third-party senders, ensuring optimal email deliverability and protecting their brand reputation. The framework should be continuously reviewed and updated to reflect changes in the email ecosystem, ensuring that the organisation remains ahead of emerging threats and challenges.
In our experience at DMARC Engine, a well-structured framework can significantly reduce the time and resources required to troubleshoot DMARC alignment issues, allowing organisations to focus on more strategic initiatives. By prioritising the development of a centre of excellence and investing in the necessary tools and expertise, organisations can optimise their DMARC setup and maintain a high level of email deliverability, even in the face of increasingly complex email ecosystems.