16 August 2026 · DMARC Engine · 37 min read
Introduction to Email Authentication Challenges in M&A
When companies undergo mergers and acquisitions, email authentication often takes a back seat to more pressing concerns, such as integrating staff, consolidating infrastructure, and navigating new organisational structures. However, neglecting email authentication can lead to significant issues with email deliverability, as we have seen time and time again at DMARC Engine. A single misstep in managing SPF, DKIM, or DMARC records can result in emails being flagged as spam or, worse still, blocked entirely by recipient mail servers.
For instance, consider a scenario where Company A acquires Company B, and both companies have their own distinct email infrastructures, including separate SPF records. If the SPF record for Company B's domain is not updated to include the IP addresses of Company A's mail servers, emails sent from Company A's servers may be rejected by recipient mail servers due to SPF failures, as illustrated by the following example of an SPF record for Company B:
companyb.com. IN TXT "v=spf1 ip4:192.0.2.1 ip4:192.0.2.2 include:companyb-mail.com -all"In this case, if Company A's mail server IP addresses are not added to Company B's SPF record, emails sent from Company A's servers will fail SPF checks, potentially leading to deliverability issues.
To mitigate such risks, it is crucial to centralise the management of email authentication protocols, particularly in a hosted or managed setup, where expertise and resources can be focused on ensuring a seamless transition. At DMARC Engine, we have developed strategies to optimise the management of SPF, DKIM, and DMARC records for our clients undergoing M&A activities.
One key challenge in M&A scenarios is the colour of the organisation's email infrastructure, which can significantly impact the complexity of email authentication management. For example, if both companies use different email service providers, such as Google Workspace and Microsoft 365, consolidating their email infrastructures will require careful planning to avoid disrupting email services.
In our experience, a centre of excellence approach, where email authentication is managed centrally, can help organisations navigate the complexities of M&A email infrastructure consolidation. This involves designating a team to oversee email authentication across the organisation, ensuring that all email-related systems and services are properly configured and aligned with the company's overall email strategy.
Another critical aspect of email authentication in M&A scenarios is the management of DKIM keys and selectors. When companies merge, their DKIM keys and selectors must be consolidated to ensure that emails sent from the merged entity are properly authenticated. This can be a complex process, particularly if the companies use different DKIM key management practices.
For example, consider a scenario where Company A uses a DKIM key with a selector named "selector1", while Company B uses a DKIM key with a selector named "selector2". If the companies merge and decide to use a single DKIM key, they must ensure that the new key is properly configured and that the selectors are updated accordingly.
At DMARC Engine, we recommend using a hosted DKIM key management service to simplify the process of managing DKIM keys and selectors. This allows organisations to centralise their DKIM key management and ensure that their DKIM keys are properly configured and aligned with their email authentication strategy.
In addition to managing SPF and DKIM records, organisations must also consider the impact of M&A activities on their DMARC implementation. DMARC is a critical component of email authentication, as it provides a mechanism for organisations to specify which email senders are authorised to send emails on their behalf.
When companies merge, their DMARC policies must be consolidated to ensure that emails sent from the merged entity are properly authenticated. This can be a complex process, particularly if the companies have different DMARC policies in place.
For example, consider a scenario where Company A has a DMARC policy of "quarantine" for emails that fail DMARC checks, while Company B has a DMARC policy of "reject" for such emails. If the companies merge, they must decide which DMARC policy to use and ensure that it is properly configured and aligned with their email authentication strategy.
At DMARC Engine, we recommend using a hosted DMARC service to simplify the process of managing DMARC policies and ensuring that emails sent from the merged entity are properly authenticated. This allows organisations to centralise their DMARC management and ensure that their DMARC policies are properly configured and aligned with their email authentication strategy.
In short, email authentication is a critical component of M&A activities, and organisations must carefully manage their SPF, DKIM, and DMARC records to ensure that emails sent from the merged entity are properly authenticated. By centralising email authentication management, using hosted or managed services, and carefully planning the consolidation of email infrastructures, organisations can navigate the complexities of M&A email authentication and ensure that their emails are delivered successfully.
To illustrate the complexity of managing email authentication in M&A scenarios, consider the following example of a DMARC record for a company that has undergone a merger:
_dmarc.companya.com. IN TXT "v=DMARC1; p=quarantine; pct=100; rua=mailto:dmarc@companya.com; ruf=mailto:dmarc@companya.com; fo=1"In this example, the DMARC record specifies a policy of "quarantine" for emails that fail DMARC checks, and it also specifies the email address to which aggregate reports and failure reports should be sent.
By carefully managing their DMARC records and ensuring that their email authentication strategy is aligned with their overall email infrastructure, organisations can ensure that their emails are delivered successfully and that their brand reputation is protected.
At DMARC Engine, we have developed a range of strategies and best practices to help organisations navigate the complexities of email authentication in M&A scenarios. By following these best practices and using hosted or managed services to centralise email authentication management, organisations can ensure that their emails are delivered successfully and that their brand reputation is protected.
In the next section, we will discuss the importance of assessing current email
Assessing Current Email Infrastructure and Authentication Protocols
When organisations undergo mergers and acquisitions, one of the critical aspects to consider is the email infrastructure and authentication protocols of the entities involved. This assessment is crucial for ensuring a seamless transition, maintaining deliverability, and preventing potential security risks. A thorough evaluation of the current setup helps in identifying potential pitfalls, such as overlapping IP addresses, conflicting SPF records, or mismatched DKIM selectors, which can lead to email delivery issues or even spam filtering.
To begin the assessment, it's essential to gather information about the email infrastructure of both organisations, including the email service providers (ESPs), mail transfer agents (MTAs), and any third-party services used for email marketing or transactional emails. For instance, if one organisation uses a cloud-based email service like Office 365, while the other relies on an on-premise Exchange server, this discrepancy can impact the authentication protocols and require careful planning for integration.
A key area of focus is the SPF (Sender Policy Framework) records, as they define which IP addresses are authorised to send emails on behalf of a domain. When merging organisations, it's common to encounter overlapping IP addresses or conflicting SPF records, which can lead to email delivery issues. For example, consider two organisations, example.com and mergedcompany.com, with the following SPF records:
example.com. IN TXT "v=spf1 ip4:192.0.2.1 ip4:198.51.100.1 include:_spf.example.net -all"
mergedcompany.com. IN TXT "v=spf1 ip4:192.0.2.1 ip4:203.0.113.1 include:_spf.mergedcompany.net -all"In this scenario, both organisations have the IP address 192.0.2.1 listed in their SPF records, which can cause issues when trying to merge the email infrastructure. To resolve this, it's necessary to consolidate the SPF records, ensuring that all authorised IP addresses are included and that there are no conflicts.
DKIM (DomainKeys Identified Mail) is another critical authentication protocol that requires attention during the assessment phase. DKIM uses a digital signature to verify the authenticity of an email, and mismatched selectors or keys can lead to delivery issues. When evaluating the DKIM setup, it's essential to consider the selector configuration, key sizes, and rotation policies. For example, if one organisation uses a 1024-bit DKIM key, while the other uses a 2048-bit key, it may be necessary to upgrade the weaker key to ensure better security and deliverability.
In a hosted or managed setup, such as the one provided by DMARC Engine, the process of assessing and consolidating email authentication protocols is streamlined through automated tools and expert guidance. These services can help identify potential issues, such as overlapping IP addresses or conflicting SPF records, and provide recommendations for resolving them. Also, managed services often include features like automated DKIM key rotation and selector management, which can simplify the process of maintaining email authentication protocols.
During the assessment phase, it's also crucial to evaluate the DMARC (Domain-based Message Authentication, Reporting, and Conformance) setup, as it provides valuable insights into the email authentication and delivery process. DMARC reports can help identify potential issues, such as unauthenticated emails or SPF/DKIM alignment problems, which can impact deliverability. For instance, a DMARC report might indicate that a significant number of emails are being sent from unauthorised IP addresses, highlighting the need for SPF record updates or additional authentication mechanisms.
To illustrate this, consider a DMARC report snippet:
<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>This report indicates that 100 emails were sent from the IP address 192.0.2.1, but both DKIM and SPF authentication failed, resulting in a DMARC failure. This information can be used to identify and address the underlying issues, such as updating the SPF record or rotating the DKIM key.
In short, assessing the current email infrastructure and authentication protocols is a critical step in navigating email authentication for mergers and acquisitions. By evaluating the SPF, DKIM, and DMARC setups, organisations can identify potential issues and develop a strategy for consolidating and optimising their email authentication protocols. This process requires careful planning, attention to detail, and a thorough understanding of the trade-offs involved in merging email infrastructures. By prioritising email authentication and deliverability, organisations can ensure a seamless transition and maintain the trust of their customers and partners.
Domain Consolidation Strategies for Merged Entities
When two or more entities merge, one of the key decisions to be made is how to consolidate their domains, which has a significant impact on email authentication. The goal is to centre the email infrastructure around a single, unified domain or a set of domains that are properly organised and authenticated. This process involves evaluating the existing domain structure, considering the colour of the brand and its online presence, and deciding whether to retain, redirect, or retire certain domains.
A common strategy is to designate a primary domain for all email communications and gradually phase out secondary domains. For instance, if Company A acquires Company B, they might decide to use companya.com as the primary domain and eventually retire companyb.com. This approach simplifies email authentication management, as it reduces the number of domains that need to be configured and monitored. In a hosted or managed setup, such as the one we operate at DMARC Engine, this consolidation can be facilitated by our platform, which allows for the easy management of multiple domains under a single umbrella.
However, domain consolidation is not without its challenges. One of the main concerns is preserving the existing email infrastructure and ensuring that all email services, including marketing campaigns and transactional emails, continue to function seamlessly. This requires careful planning and execution to avoid any disruptions to email services. For example, when consolidating domains, it is crucial to update the DNS records, including SPF, DKIM, and DMARC records, to reflect the changes.
# Example of an updated SPF record for the primary domain
companya.com. IN TXT "v=spf1 ip4:192.0.2.1 ip4:198.51.100.1 include:_spf.companya.com -all"In this example, the SPF record for companya.com includes the IP addresses of the mail servers for both Company A and Company B, ensuring that emails sent from either domain are authenticated correctly.
Another important consideration is the management of DKIM keys and selectors. When consolidating domains, it may be necessary to generate new DKIM keys or update the existing ones to ensure that emails sent from the primary domain are properly signed. This can be a complex process, especially if the merged entities have different email service providers or infrastructure.
# Example of a DKIM key record
default._domainkey.companya.com. IN TXT "v=DKIM1; k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC+yt4zo9XNFQfrk41EjYap4pVXw2gHj9NzTIKJ/eY7nO9Q+7jLJraXyHm3lYVxgTzZS3R4POXPcRf4u1BQaUw7pQK0lTb6WQDwJH2t3d8Jn9rQxK0lTb6WQDwJH2t3d8Jn9"In a hosted setup, our platform at DMARC Engine can optimise the DKIM key management process by automatically generating and updating DKIM keys, as well as configuring the necessary DNS records.
Domain consolidation also requires careful consideration of the DMARC policy. When merging domains, it is essential to ensure that the DMARC policy is aligned across all domains to prevent any potential issues with email deliverability. This may involve updating the DMARC record to reflect the new domain structure and ensuring that all email services are configured to use the correct DMARC policy.
# Example of a DMARC record
_dmarc.companya.com. IN TXT "v=DMARC1; p=reject; pct=100; rua=mailto:aggrep@companya.com; ruf=mailto:forensics@companya.com; fo=1"In this example, the DMARC record for companya.com specifies a reject policy for all emails that fail DMARC authentication, which helps to prevent spam and phishing attacks.
Ultimately, the key to successful domain consolidation is careful planning, precise execution, and ongoing monitoring. By centralising email infrastructure around a primary domain and properly configuring email authentication protocols, merged entities can ensure a smooth transition and maintain optimal email deliverability. As a hosted and managed service provider, we at DMARC Engine are well-positioned to guide our customers through this process, helping them to navigate the complexities of domain consolidation and email authentication.
Navigating SPF Record Mergers and Avoiding IP Address Overlap
When organisations undergo mergers and acquisitions, one of the critical aspects of email infrastructure integration is managing SPF (Sender Policy Framework) records. SPF is a protocol that helps prevent spam by allowing domain owners to specify which IP addresses are authorised to send emails on their behalf. Merging SPF records from different entities can be complex, especially when dealing with overlapping IP addresses, varying mail server configurations, and the need to optimise record sizes to avoid DNS query limits.
A common challenge is deciding how to consolidate SPF records without causing deliverability issues. For instance, consider a scenario where Company A, with the domain companya.com, has an SPF record that includes IP addresses from its own mail servers and a third-party mailing service:
v=spf1 ip4:192.0.2.1 ip4:198.51.100.1 include:_spf.examplemailservice.com -allMeanwhile, Company B, with the domain companyb.com, has its own SPF record that includes different IP addresses and another third-party service:
v=spf1 ip4:203.0.113.1 ip4:200.160.0.1 include:_spf.anotherservice.com -allUpon merging, the goal is to create a single, comprehensive SPF record that accurately represents all authorised mail servers and services for both companies without exceeding the 255-character limit per DNS query or causing IP address overlap issues.
To navigate this, it's essential to conduct a thorough inventory of all IP addresses and mail services used by both companies. This includes not just their own mail servers but also any third-party services, such as marketing automation platforms, CRM systems, or cloud services that send emails on their behalf. For each entity, list all the IP addresses and include statements from third-party services. Then, consolidate these into a single list, removing any duplicates.
In a hosted or managed setup, such as what we provide at DMARC Engine, tools are available to help simplify this process, including automated SPF record builders and validators that can check for errors and optimise record length. For example, our platform can analyse the mail flow and automatically generate an SPF record that includes all necessary IP addresses and services, while also ensuring the record stays within the character limit.
However, even with these tools, manual oversight is crucial to ensure that no critical mail servers or services are overlooked and that the record is properly validated. It's also important to consider the impact of IP address overlap, where the same IP address is used by both companies for different purposes. In such cases, careful planning is needed to ensure that the SPF record accurately reflects the mail sending practices of the merged entity.
To avoid IP address overlap issues, it may be necessary to reconfigure mail servers or work with third-party services to allocate unique IP addresses for each entity's mail streams. This can be particularly challenging when dealing with cloud services that may not offer dedicated IP addresses or when the IP addresses are dynamically allocated.
In terms of best practices for merging SPF records, it's recommended to use the include mechanism sparingly, as it can lead to record bloat and make troubleshooting more difficult. Instead, where possible, list IP addresses directly in the SPF record. Also, consider using IP address blocks (e.g., ip4:192.0.2.0/24) instead of individual IP addresses to reduce the record size and improve manageability.
After consolidating the SPF records, it's critical to test the new record thoroughly to ensure it does not cause deliverability issues. This involves sending test emails from all identified mail servers and services to check for SPF failures and adjusting the record as needed. Tools like our DMARC Engine platform can provide insights into SPF alignment issues through aggregate report analysis, helping to identify and resolve problems promptly.
In the context of mergers and acquisitions, the management of SPF records is just one aspect of a broader email authentication strategy that includes DKIM, DMARC, and potentially other protocols like BIMI and MTA-STS. Effective management of these protocols requires a deep understanding of the email ecosystem, the ability to analyse complex data sets, and the capacity to make informed decisions about infrastructure configurations and policy settings.
Ultimately, navigating SPF record mergers and avoiding IP address overlap requires careful planning, meticulous execution, and ongoing monitoring to ensure the merged entity's email infrastructure is secure, compliant, and optimised for deliverability. By taking a proactive and informed approach to SPF record management, organisations can mitigate the risks associated with email authentication in mergers and acquisitions and maintain a strong foundation for their email communications.
DKIM Key Management and Selector Configuration in M&A Scenarios
When organisations undergo mergers and acquisitions, managing DomainKeys Identified Mail (DKIM) keys and selectors becomes a critical task to ensure seamless email authentication and deliverability. A key consideration is how to handle the consolidation of DKIM keys and selectors from the merging entities. In a hosted setup, such as the one we manage at DMARC Engine, this process involves careful planning to avoid any disruption to email services.
One of the primary challenges is deciding whether to use a single DKIM key and selector for all merged domains or to maintain separate keys and selectors for each domain. Using a single key and selector can simplify management but may not be ideal from a security and organisational perspective. For instance, if a single key is compromised, it could affect all domains using that key. On the other hand, maintaining separate keys and selectors for each domain can enhance security but increases the complexity of key management.
In practice, we often see organisations opting for a hybrid approach, where related domains or subdomains share a DKIM key and selector, while unrelated domains maintain their own keys and selectors. For example, if two companies, example.com and example.net, merge, they might decide to use the same DKIM key and selector for both domains if they are closely related, but use separate keys and selectors if they operate independently.
To illustrate this, consider a scenario where example.com and example.net decide to share a DKIM key and selector. Their DKIM record might look like this:
default._domainkey.example.com. IN TXT "v=DKIM1; k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCqGKukO1De7zhZj6+H0qtjTkVxwTCpvKe4eCZ0FPqri0cb2JZfXJ/DgYSF6vUpwmJG8wVQZKjeGcjDOL5UlsuusFncCzWBQ7RKNUSesmQRMSGkVb1/3j+skZ6UtW+5u09lHNsj6tQ51s1SPrCBkedbNf0Tp0GbMJDyR4e9T04ZZwIDAQAB; s=email; t=s;"
default._domainkey.example.net. IN TXT "v=DKIM1; k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCqGKukO1De7zhZj6+H0qtjTkVxwTCpvKe4eCZ0FPqri0cb2JZfXJ/DgYSF6vUpwmJG8wVQZKjeGcjDOL5UlsuusFncCzWBQ7RKNUSesmQRMSGkVb1/3j+skZ6UtW+5u09lHNsj6tQ51s1SPrCBkedbNf0Tp0GbMJDyR4e9T04ZZwIDAQAB; s=email; t=s;"Notice that both domains use the same public key (p parameter) and selector (default), indicating they share the same DKIM key and selector.
However, if example.io is acquired by example.com but operates independently, it might be preferable for example.io to have its own DKIM key and selector for security and management reasons. In this case, the DKIM record for example.io would be different:
default._domainkey.example.io. IN TXT "v=DKIM1; k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDd4O3yHj1y2p9fjT0L1j2d2l2j2d2j2d2j2d2j2d2j2d2l2j2d2j2d2l2j2d2j2d2l2j2d2j2d2l2j2d2j2d2l2j2d2j2d2j2d2l2j2d2j2d2l2j2d2j2d2j2d2l2j2d2j2d2l2j2d2j2d2j2d2l2j2d2j2d2l2j2d2j2d2l2j2d2j2d2j2d2l2j2d2j2d2l2j2d2j2d2j2d2j2d2l2j2d2j2d2l2j2d2j2d2j2d2j2d2l2j2d2j2d2l2j2d2j2d2j2d2j2d2l2j2d2j2d2l2j2d2j2d2j2d2j2d2j2d2l2j2d2j2d2l2j2d2j2d2j2d2j2d2j2d2l2j2d2j2d2l2j2d2j2d2j2d2l2j2d2j2d2j2d2j2d2j2d2l2j2d2j2d2l2j2d2j2d2j2d2j2d2j2d2l2j2d2j2d2l2j2d2j2d2j2d2j2d2j2d2j2d2l2j2d2j2d2l2j2d2j2d2j2d2l2j2d2j2d2j2d2j2d2j2d2l2j2d2j2d2l2j2d2j2d2j2d2j2d2j2d2j2d2l2j2d2j2d2l2j2d2j2d2j2d2j2d2j2d2j2d2l2j2d2j2d2l2j2d2j2d2j2d2l2j2d2j2d2j2d2j2d2j2d2l2j2d2j2d2l2j2d2j2d2j2d2j2d2j2d2j2d2l2j2d2j2d2l2j2d2j2d2j2d2l2j2d2j2d2j2d2j2d2j2d2l2j2d2j2d2
## Implementing and Managing DMARC Across Merged Domains
When organisations undergo mergers and acquisitions, one of the critical aspects to consider is the management of Domain-based Message Authentication, Reporting, and Conformance (DMARC). DMARC is a protocol that helps prevent email spoofing by verifying the authenticity of an email message, ensuring it comes from the domain it claims to be from. Managing DMARC across merged domains can be complex, requiring careful planning and execution to avoid disruptions to email services and to maintain deliverability.
A key challenge in implementing DMARC across merged domains is dealing with the varying levels of DMARC adoption and configuration within each organisation. For instance, one company might have a strict DMARC policy (e.g., `p=reject`) in place for all its domains, while the other might not have DMARC set up at all. This discrepancy can lead to issues when trying to consolidate email services under a unified domain or set of domains.
To mitigate these risks, it's essential to conduct a thorough assessment of the current DMARC setup for each domain involved in the merger. This includes checking the DMARC policy, the percentage of messages to which the policy is applied (`pct` tag), and the alignment modes (`adkim` and `aspf` tags). For example, consider a scenario where Company A has the following DMARC record:
_dmarc.example.com. IN TXT "v=DMARC1; p=none; pct=100; rua=mailto:dmarc@example.com; ruf=mailto:dmarc@example.com; fo=1"
Meanwhile, Company B, which is being acquired, has a more restrictive policy:
_dmarc.example.net. IN TXT "v=DMARC1; p=reject; pct=100; rua=mailto:dmarc@example.net; ruf=mailto:dmarc@example.net; fo=1"
In this case, deciding on a unified DMARC policy that balances security with the need to avoid falsely rejecting legitimate emails is crucial. A hosted or managed DMARC setup can provide tools to simplify this process, such as automated policy suggestions based on aggregate report analysis.
Another critical aspect of managing DMARC across merged domains is handling the reporting and analysis of DMARC data. DMARC aggregate reports (RUA) provide valuable insights into email authentication issues, helping organisations identify and fix problems that could lead to email deliverability issues. However, when dealing with multiple domains, especially in a post-merger scenario, managing these reports can become cumbersome. Utilising a centralised platform for DMARC report analysis can help streamline this process, offering features such as report aggregation, automated issue detection, and recommendations for policy adjustments.
When implementing DMARC across merged domains, organisations must also consider the impact on their email deliverability. A strict DMARC policy can help protect a domain from spoofing but may also lead to legitimate emails being rejected if they do not align with the domain's DMARC policy. This is particularly relevant in scenarios where companies use third-party senders that might not be fully compliant with DMARC. To optimise deliverability while maintaining security, organisations may choose to start with a monitoring-only policy (`p=none`) and gradually move towards a more restrictive policy as they work with their senders to ensure compliance.
The process of merging DMARC configurations also presents an opportunity to review and optimise the overall email authentication setup. This includes ensuring that Sender Policy Framework (SPF) and DomainKeys Identified Mail (DKIM) configurations are aligned and correctly set up for all domains involved. For DKIM, this means managing selectors and ensuring that all sending sources are configured to use the appropriate DKIM keys. For SPF, it involves consolidating IP addresses and ensuring that all legitimate sending sources are included in the SPF record without exceeding the 10 lookup limit.
In terms of best practices for implementing and managing DMARC across merged domains, organisations should:
- Conduct a comprehensive audit of existing DMARC, SPF, and DKIM configurations for all involved domains.
- Develop a unified strategy for email authentication that balances security with deliverability needs.
- Utilise centralised management tools for DMARC and other email authentication protocols to simplify configuration and reporting.
- Gradually implement DMARC policies, starting with monitoring and moving towards enforcement as senders are validated and aligned.
- Continuously monitor DMARC reports and adjust policies as necessary to maintain optimal deliverability and security.
By following these guidelines and carefully considering the complexities of managing DMARC across merged domains, organisations can protect their brands from spoofing, ensure the deliverability of their emails, and maintain a secure and reliable email ecosystem throughout the merger and acquisition process.
## Aggregate Report Analysis for Troubleshooting and Optimisation
Aggregate report analysis is a crucial step in troubleshooting and optimising email authentication for merged entities. As a senior email-deliverability engineer, I can attest that daily analysis of aggregate reports, also known as Reporting Using Aggregated Data (RUA) reports, is essential for identifying issues and making data-driven decisions. These reports provide valuable insights into email authentication results, helping organisations to identify and resolve problems that may impact deliverability.
When analysing aggregate reports, it is essential to focus on the key metrics that indicate authentication issues. One of the most critical metrics is the percentage of emails that fail DMARC authentication. For example, if an organisation sees a high percentage of emails failing DMARC authentication, it may indicate a problem with the SPF or DKIM configuration. json
{
"org_name": "example.com",
"date_range": {
"start": "2022-01-01",
"end": "2022-01-31"
},
"records": [
{
"source_ip": "192.0.2.1",
"count": 100,
"disposition": "none",
"dkim": "fail",
"spf": "pass"
},
{
"source_ip": "192.0.2.2",
"count": 50,
"disposition": "quarantine",
"dkim": "pass",
"spf": "fail"
}
]
}
In this example, the report shows that 100 emails from the IP address 192.0.2.1 failed DKIM authentication, while 50 emails from the IP address 192.0.2.2 failed SPF authentication. This information can help the organisation to identify the specific authentication issues and take corrective action.
Another important aspect of aggregate report analysis is identifying and mitigating potential threats. For instance, if an organisation notices a sudden increase in emails failing DMARC authentication from a specific IP address, it may indicate a spamming or phishing attack. In such cases, the organisation can take swift action to block the IP address and prevent further abuse. json
{
"org_name": "example.com",
"date_range": {
"start": "2022-02-01",
"end": "2022-02-28"
},
"records": [
{
"source_ip": "192.0.2.3",
"count": 500,
"disposition": "reject",
"dkim": "fail",
"spf": "fail"
}
]
}
In this example, the report shows that 500 emails from the IP address 192.0.2.3 failed both DKIM and SPF authentication, resulting in a reject disposition. This could indicate a potential spamming or phishing attack, and the organisation should take immediate action to block the IP address.
In a hosted or managed setup, aggregate report analysis can be simplified through automated tools and expert analysis. For example, DMARC Engine's managed service provides daily aggregate report analysis, identifying potential issues and providing recommendations for optimisation. This can be particularly useful for organisations that lack the in-house expertise or resources to analyse aggregate reports effectively.
When analysing aggregate reports, it is also essential to consider the impact of domain consolidation on email authentication. In a merger or acquisition scenario, domain consolidation can lead to complex email authentication issues. For instance, if two organisations merge, they may need to consolidate their domains and update their email authentication configurations accordingly. json
{
"org_name": "example.com",
"date_range": {
"start": "2022-03-01",
"end": "2022-03-31"
},
"records": [
{
"source_ip": "192.0.2.4",
"count": 200,
"disposition": "none",
"dkim": "fail",
"spf": "pass"
},
{
"source_ip": "192.0.2.5",
"count": 100,
"disposition": "quarantine",
"dkim": "pass",
"spf": "fail"
}
]
}
In this example, the report shows that 200 emails from the IP address 192.0.2.4 failed DKIM authentication, while 100 emails from the IP address 192.0.2.5 failed SPF authentication. This could indicate issues with the consolidated domain's email authentication configuration, and the organisation should take corrective action to resolve these issues.
To optimise email authentication, organisations should also focus on improving their DMARC, SPF, and DKIM configurations. For example, organisations can improve their DMARC configuration by setting a stricter policy, such as `p=quarantine` or `p=reject`, to reduce the risk of spam and phishing attacks. xml
<?xml version="1.0" encoding="UTF-8"?>
<feedback>
<version>1</version>
<policy_published>
<domain>example.com</domain>
<adkim>r</adkim>
<aspf>r</aspf>
<p>quarantine</p>
<sp>none</sp>
<pct>100</pct>
</policy_published>
</feedback>
In this example, the DMARC policy is set to `p=quarantine`, which means that emails that fail DMARC authentication will be quarantined. This can help to reduce the risk of spam and phishing attacks.
In addition to improving DMARC configurations, organisations should also focus on optimising their SPF and DKIM configurations. For example, organisations can improve their SPF configuration by adding more IP addresses to the SPF record, or by using a more restrictive SPF policy, such as `v=spf1 ip4:192.0.2.1 -all`. plain
v=spf1 ip4:192.0.2.1 ip4:192.0.2.2 -all
In this example, the SPF record includes two IP addresses, 192.0.2.1 and 192.0.2.2, and uses a restrictive policy, `-all`, to prevent spam and phishing attacks.
Similarly, organisations can improve their DKIM configuration by using a stronger cryptographic algorithm, such as `rsa-sha256`, or by using a more secure selector configuration, such as `s1._domainkey.example.com`. plain
s1._domainkey.example.com. 3600 IN TXT "v=DKIM1; k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCqGKukO1De7zhZj6+H0qtjTkVxwTCpvKe4eCZ0FPqri0cb2JZfXJ/DgYSF6vUpwmJG8wVQZKjeGcjDOL5UlsuusFncCzWBQ7RKNUSesmQRMSGkVb1/3j+skZ6UtW+5u09lHNsj6tQ51s1SPrCBkedbNf0Tp0GbMJDyR4e9T04ZZwIDAQAB"
In this example, the DKIM record uses a strong cryptographic algorithm, `rsa-sha256`, and a secure selector configuration, `s1._domainkey.example.com`, to prevent spam and phishing attacks.
In conclusion to this section, aggregate report analysis is a critical component of email authentication, particularly in merger and acquisition scenarios. By analysing aggregate reports, organisations can identify and resolve email authentication issues, mitigate potential threats, and optimise their DMARC, SPF, and DKIM configurations to improve deliverability and prevent spam and phishing attacks. As a senior email-deliverability engineer, I strongly recommend that organisations prioritise aggregate report analysis and invest in the necessary tools and expertise to ensure the security and deliverability
## BIMI and MTA-STS Deployment Considerations in Post-Merger Environments
When navigating the complexities of email authentication in mergers and acquisitions, BIMI (Brand Indicators for Message Identification) and MTA-STS (Mail Transfer Agent Strict Transport Security) are often overlooked, yet they play a critical role in maintaining the security and deliverability of emails. In a post-merger environment, deploying BIMI and MTA-STS requires careful consideration to ensure seamless integration and to avoid potential pitfalls.
Firstly, let's consider BIMI, which allows brands to display their logos next to authenticated emails, enhancing the recipient's trust and brand recognition. In a merged entity, it's essential to consolidate BIMI records to reflect the new brand identity. For instance, if Company A acquires Company B, they may want to display a single, unified logo across all emails. To achieve this, they would need to update the BIMI records for both companies to point to the new logo.
default._bimi.example.com. 3600 IN TXT "v=BIMI1; l=https://example.com/logo.svg; a=;"
In this example, the BIMI record for `example.com` points to a logo located at `https://example.com/logo.svg`. When managing BIMI records in a hosted setup, such as DMARC Engine, it's crucial to ensure that the logo URL is accessible and that the record is properly configured to avoid any issues with email deliverability.
MTA-STS, on the other hand, is a protocol that ensures emails are transmitted securely over TLS (Transport Layer Security). In a post-merger environment, MTA-STS deployment requires careful planning to avoid disrupting email services. One common challenge is ensuring that all mail servers support MTA-STS and are configured correctly. For example, if Company A uses a different mail server than Company B, they may need to update their MTA-STS records to reflect the new mail server configuration.
_mta-sts.example.com. 3600 IN TXT "v=STSv1; id=2023022201;"
In this example, the MTA-STS record for `example.com` specifies the version and ID of the policy. When deploying MTA-STS in a managed setup, it's essential to ensure that all mail servers are properly configured and that the records are updated to reflect any changes in the mail server infrastructure.
A key consideration when deploying BIMI and MTA-STS in a post-merger environment is the potential impact on email deliverability. If not properly configured, these protocols can lead to email delivery issues, such as emails being marked as spam or blocked by recipients' mail servers. To mitigate this risk, it's crucial to monitor email deliverability closely and to troubleshoot any issues promptly. In a hosted setup, such as DMARC Engine, this can be achieved through the use of aggregate reports, which provide valuable insights into email deliverability and authentication issues.
Another important aspect to consider is the management of BIMI and MTA-STS records in a post-merger environment. In a hosted setup, such as DMARC Engine, records can be easily managed and updated through a centralised dashboard. However, in a self-managed setup, records may need to be updated manually, which can be time-consuming and prone to errors. To optimise record management, it's recommended to use a automated tool, such as a DNS manager, to streamline the process and reduce the risk of errors.
In terms of best practices, it's recommended to follow a phased approach when deploying BIMI and MTA-STS in a post-merger environment. This involves initially deploying the protocols on a small scale, monitoring their impact on email deliverability, and then gradually rolling them out to the entire organisation. Also, it's essential to ensure that all stakeholders, including IT teams and marketing departments, are aware of the deployment and its potential impact on email services.
To illustrate the importance of careful planning and deployment, consider the example of a large retail company that acquired a smaller competitor. The retail company had already deployed BIMI and MTA-STS, but the smaller competitor had not. To ensure a seamless integration, the retail company needed to update the BIMI and MTA-STS records for the smaller competitor to reflect their new brand identity and mail server configuration. By following a phased approach and carefully monitoring email deliverability, the retail company was able to successfully deploy BIMI and MTA-STS across the entire organisation, enhancing the security and deliverability of their emails.
In conclusion to this section, deploying BIMI and MTA-STS in a post-merger environment requires careful consideration and planning to ensure seamless integration and to avoid potential pitfalls. By following best practices, such as a phased approach and careful monitoring of email deliverability, organisations can successfully deploy these protocols and enhance the security and deliverability of their emails. In a hosted setup, such as DMARC Engine, the process can be streamlined and simplified, reducing the risk of errors and ensuring a smooth transition.
## Operational Guidance for Email Authentication Protocol Migration
When organisations undergo mergers and acquisitions, one of the critical aspects that can easily be overlooked is the migration of email authentication protocols. This process involves a series of complex steps, each with its own set of challenges and considerations. A key decision point is how to handle the consolidation of SPF records, management of DKIM keys, and implementation of DMARC across merged domains.
In our experience at DMARC Engine, where we host and manage DMARC, SPF, DKIM, MTA-STS, and BIMI for our customers, we have seen firsthand the importance of careful planning and execution in email authentication protocol migration. For instance, when two companies merge, their respective SPF records must be consolidated to ensure that all legitimate sending IPs are included, while avoiding IP address overlap that could lead to authentication failures.
Consider a scenario where Company A, with the domain `companya.com`, has an SPF record that includes IPs from its own mail servers and a third-party marketing service:
companya.com. IN TXT "v=spf1 ip4:192.0.2.1 ip4:198.51.100.1 include:_spf.marketing-service.com -all"
Meanwhile, Company B, with the domain `companyb.com`, has its own SPF record:companyb.com. IN TXT "v=spf1 ip4:203.0.113.1 ip4:200.160.0.1 include:_spf.another-service.com -all"
When these companies merge, their SPF records need to be combined in a way that includes all the necessary IPs without exceeding the 10 lookup limit imposed by the SPF protocol. This might involve creating a new SPF record that includes all the IPs from both companies, potentially using macros or subdomains to organise the records and stay within the lookup limit.
DKIM key management presents another challenge. Each company may have its own set of DKIM keys, and deciding which keys to retain, which to replace, and how to manage selectors can be complex. For example, if Company A uses a DKIM key with the selector `default`:
default._domainkey.companya.com. IN TXT "v=DKIM1; k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC+Gv9K6r2d5wY7zjVZ6w1vzK7HjH5sJH2km6yXyjX8x8x8x8x8x8x8x"
And Company B uses a key with the selector `mail`:
mail._domainkey.companyb.com. IN TXT "v=DKIM1; k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC+XxXxXxXxXxXxXxXxXxXxXxXxXxXxXxXx"
The merged company must decide whether to use one set of keys, combine them under a new selector, or implement a completely new DKIM key strategy. This decision has implications for email deliverability, as DKIM validation failures can lead to emails being flagged as spam or rejected outright.
DMARC implementation across merged domains also requires careful consideration. DMARC policies must be aligned across all domains to ensure consistent handling of emails that fail authentication. If one domain has a DMARC policy set to `none`, while another has a policy set to `reject`, this discrepancy can lead to inconsistent email handling and potential deliverability issues. For example, if `companya.com` has a DMARC record with a `none` policy:
_dmarc.companya.com. IN TXT "v=DMARC1; p=none; pct=100; rua=mailto:aggrep@companya.com; ruf=mailto:forensicp@companya.com; fo=1"
And `companyb.com` has a DMARC record with a `reject` policy:
_dmarc.companyb.com. IN TXT "v=DMARC1; p=reject; pct=100; rua=mailto:aggrep@companyb.com; ruf=mailto:forensicp@companyb.com; fo=1"
The merged entity should align these policies, potentially moving towards a more restrictive policy like `reject` to better protect against phishing attacks, but only after ensuring that all legitimate email sources are properly authenticated.
In a hosted or managed setup, such as what we offer at DMARC Engine, the process of migrating and managing email authentication protocols can be significantly streamlined. Our platform allows for the easy consolidation of SPF records, management of DKIM keys, and implementation of DMARC policies across multiple domains. This not only reduces the complexity and workload associated with these tasks but also minimises the risk of errors that could impact email deliverability.
However, even with managed services, it is crucial for organisations to understand the underlying mechanics of email authentication protocols and the implications of their configuration choices. This knowledge is essential for making informed decisions about how to best consolidate and manage these protocols during a merger or acquisition.
Ultimately, the key to successful email authentication protocol migration is meticulous planning, careful execution, and ongoing monitoring. Organisations must be prepared to address the unique challenges that arise from consolidating email infrastructure and authentication protocols, and they must do so in a way that prioritises email deliverability and security. By understanding the specifics of SPF, DKIM, and DMARC migration, and by leveraging the benefits of hosted or managed services where appropriate, organisations can navigate the complexities of email authentication in a post-merger environment with confidence.
## Best Practices for Preserving Deliverability Through M&A Transitions
Preserving deliverability during mergers and acquisitions requires meticulous planning, execution, and ongoing monitoring. A key consideration is the consolidation of email authentication protocols, including DMARC, SPF, and DKIM. When organisations merge, their email infrastructures often become intertwined, leading to complexities in managing these protocols. For instance, our team at DMARC Engine has seen cases where companies have inadvertently blocked their own emails due to overly restrictive SPF records.
To avoid such issues, it is crucial to conduct a thorough assessment of the current email infrastructure and authentication protocols of both entities. This includes reviewing SPF records, such as the following example:
v=spf1 ip4:192.0.2.1 ip4:198.51.100.1 include:_spf.example.com -all
```
In this example, the SPF record includes two IP addresses and an include statement for a third-party service. When consolidating SPF records during an M&A, it is essential to ensure that all IP addresses and include statements are correctly merged to avoid IP address overlap or unintended blocking of emails.
Another critical aspect is DKIM key management and selector configuration. When companies merge, their DKIM keys and selectors may need to be consolidated or updated. For example, if Company A has a DKIM key with the selector s1, and Company B has a DKIM key with the selector s2, the merged entity may need to decide which selector to use or create a new one. Our experience has shown that using a hosted or managed DKIM setup can simplify this process by providing a centralised platform for managing DKIM keys and selectors.
Implementing and managing DMARC across merged domains is also vital for preserving deliverability. DMARC provides a mechanism for email receivers to report back to the sender about the authentication status of emails. By monitoring DMARC aggregate reports, organisations can identify potential issues with their email authentication setup and take corrective action. For instance, our team has seen cases where organisations have received DMARC reports indicating that their emails are being spoofed, allowing them to take swift action to mitigate the issue.
In addition to technical considerations, it is essential to establish clear communication channels and processes for managing email authentication protocols during an M&A. This includes designating a central team or individual to oversee email authentication, establishing protocols for updating SPF and DKIM records, and ensuring that all stakeholders are informed of changes to the email infrastructure.
To optimise deliverability, organisations should also consider implementing BIMI (Brand Indicators for Message Identification) and MTA-STS (Mail Transfer Agent Strict Transport Security). BIMI allows organisations to specify a logo to be displayed next to their emails in supporting email clients, providing an additional layer of authentication and brand visibility. MTA-STS, on the other hand, provides a mechanism for email senders to specify their transport security preferences, helping to prevent email interception and tampering.
When migrating email authentication protocols during an M&A, it is crucial to follow a structured approach. This includes assessing the current infrastructure, developing a migration plan, and testing the new setup before implementing it in production. Our team has found that using a phased approach, where changes are rolled out gradually, can help to minimise disruptions and ensure a smooth transition.
In terms of specific recommendations, we advise organisations to:
- Conduct regular audits of their email infrastructure and authentication protocols to identify potential issues and areas for improvement
- Establish a centralised platform for managing email authentication protocols, such as a hosted or managed DMARC setup
- Use a phased approach when migrating email authentication protocols to minimise disruptions and ensure a smooth transition
- Monitor DMARC aggregate reports regularly to identify potential issues with email authentication and take corrective action
- Consider implementing BIMI and MTA-STS to provide an additional layer of authentication and brand visibility
By following these best practices and considering the complexities of email authentication during mergers and acquisitions, organisations can help to preserve deliverability and ensure that their emails reach their intended recipients. As our team has seen firsthand, careful planning, execution, and ongoing monitoring are essential for navigating the challenges of email authentication in M&A scenarios.
In our experience, one of the most common mistakes organisations make during an M&A is to underestimate the complexity of consolidating email authentication protocols. This can lead to unintended consequences, such as email blocking or spoofing. To avoid such issues, it is essential to work with a team that has experience in managing email authentication protocols and can provide guidance on the best approach for the organisation.
Ultimately, preserving deliverability during mergers and acquisitions requires a deep understanding of email authentication protocols and a structured approach to managing them. By following the best practices outlined above and seeking guidance from experienced professionals, organisations can help to ensure that their emails are delivered successfully and that their brand reputation is protected.
To illustrate this point, consider the example of a company that recently underwent a merger. The company had a complex email infrastructure, with multiple domains and email authentication protocols in place. To consolidate the email infrastructure and preserve deliverability, the company worked with our team to develop a customised plan for managing email authentication protocols. This included implementing a hosted DMARC setup, consolidating SPF records, and updating DKIM keys and selectors. As a result, the company was able to ensure that its emails were delivered successfully and that its brand reputation was protected.
In conclusion to this section, the key to preserving deliverability during mergers and acquisitions is to carefully plan, execute, and monitor the consolidation of email authentication protocols. By following the best practices outlined above and seeking guidance from experienced professionals, organisations can help to ensure that their emails are delivered successfully and that their brand reputation is protected.