Email Auth Disaster

21 August 2026 · DMARC Engine · 42 min read

Email Authentication for Disaster Recovery and Business Continuity Planning

Data Centre Outages and Email Authentication Failures

Data centre outages can have a significant impact on email authentication, leading to failures that may result in email delivery issues. When a data centre experiences an outage, it can affect the availability of DNS records, including those used for email authentication such as SPF, DKIM, and DMARC. For instance, if a company's DNS servers are hosted in the affected data centre, their SPF record may become unavailable, causing email senders to fail SPF checks.
A real-world example of this is when a large cloud provider experienced a widespread outage, affecting several major companies, including email service providers. During this outage, many organisations saw a significant increase in email delivery failures due to the unavailability of their DNS records.
To mitigate this risk, organisations can use a hosted or managed DNS service that has built-in redundancy and failover capabilities. For example, a hosted DNS service may have multiple data centres in different locations, ensuring that DNS records remain available even in the event of a data centre outage.
In a managed setup, the hosting provider typically handles the DNS configuration, including email authentication records. This can be beneficial for organisations that do not have the in-house expertise to manage their own DNS infrastructure. However, it is essential to carefully evaluate the hosting provider's disaster recovery and business continuity plans to ensure they meet the organisation's requirements.
One common mistake organisations make is not having a backup plan for their DNS records. This can be as simple as having a secondary DNS provider that can take over in the event of a primary provider outage.
For example, an organisation may have their primary DNS hosted with a cloud provider, but also have a secondary DNS hosted with a different provider. This way, if the primary provider experiences an outage, the secondary provider can take over, ensuring that DNS records remain available.
The following is an example of a DNS record that can be used to configure a secondary DNS provider:

; Secondary DNS configuration
@ IN NS ns1.secondary-dns.com
@ IN NS ns2.secondary-dns.com

In this example, the organisation is configuring their domain to use a secondary DNS provider, with two name servers (ns1.secondary-dns.com and ns2.secondary-dns.com) that can take over in the event of a primary provider outage.
Another important consideration is the use of a disaster recovery DNS service that can automatically switch to a backup DNS server in the event of an outage. These services typically use real-time monitoring and automated failover to ensure that DNS records remain available.
For instance, a disaster recovery DNS service may use BGP routing to automatically switch to a backup DNS server if the primary server becomes unavailable. This can help to minimise downtime and ensure that email authentication records remain available.
To illustrate this, consider the following example of a BGP routing configuration:

; BGP routing configuration
bgp 64512
 bgp log-neighbor-changes
 neighbor 10.0.0.1 remote-as 64512
 neighbor 10.0.0.1 route-map PRIMARY out
 neighbor 10.0.0.2 remote-as 64512
 neighbor 10.0.0.2 route-map BACKUP out

In this example, the organisation is configuring BGP routing to use a primary and backup DNS server. The route-map PRIMARY out and route-map BACKUP out statements are used to specify the routing rules for the primary and backup servers, respectively.
In the event of a primary server outage, the BGP routing configuration can automatically switch to the backup server, ensuring that DNS records remain available.
In addition to using a hosted or managed DNS service, organisations can also use DNS record redundancy to mitigate the risk of data centre outages. This involves configuring multiple DNS records for the same resource, such as multiple MX records for email delivery.
For example, an organisation may have the following MX records configured:

; MX record configuration
@ IN MX 10 mail1.example.com
@ IN MX 20 mail2.example.com
@ IN MX 30 mail3.example.com

In this example, the organisation is configuring multiple MX records for email delivery, with different priority values (10, 20, and 30). If the primary mail server (mail1.example.com) becomes unavailable, email can be delivered to the secondary mail server (mail2.example.com), and so on.
By using DNS record redundancy, organisations can help to ensure that email delivery remains available even in the event of a data centre outage.
However, it is essential to carefully evaluate the trade-offs of using DNS record redundancy, such as the increased complexity of DNS configuration and the potential for email delivery delays.
In short, data centre outages can have a significant impact on email authentication, leading to failures that may result in email delivery issues. To mitigate this risk, organisations can use a hosted or managed DNS service, configure a secondary DNS provider, use a disaster recovery DNS service, and implement DNS record redundancy.
By taking a proactive approach to email authentication and disaster recovery, organisations can help to ensure that their email delivery remains available and reliable, even in the event of a data centre outage.
It is also crucial to regularly test and evaluate the organisation's disaster recovery and business continuity plans to ensure they are effective and up-to-date.
This can involve conducting regular drills and simulations to test the organisation's response to a data centre outage, as well as evaluating the effectiveness of their DNS configuration and email authentication records.
By doing so, organisations can help to ensure that their email delivery remains available and reliable, even in the face of unexpected disruptions.

Domain Registrar Failures: A Hidden Email Deliverability Risk

Domain registrar failures can have a significant impact on email deliverability, particularly when it comes to DNS-based authentication protocols such as DMARC, SPF, and DKIM. A failure to renew a domain or a registrar's DNS outage can render these protocols useless, leading to email delivery issues. For instance, if a domain's DNS is unavailable, mail servers will be unable to perform SPF checks or verify DKIM signatures, which can result in emails being flagged as spam or rejected outright.

A real-world example of this is when a major domain registrar experienced a DNS outage, affecting thousands of domains. One of our customers, a large e-commerce company, was impacted by this outage, and their emails were being rejected by mail servers due to failed SPF checks. The company's DMARC record, which was set up to monitor and enforce SPF and DKIM authentication, was also affected, as the DNS outage prevented mail servers from accessing the record.

_dmarc.example.com. IN TXT "v=DMARC1; p=reject; pct=100; rua=mailto:rua@example.com; ruf=mailto:ruf@example.com; fo=1"

In this scenario, the company's email deliverability was severely impacted, and they were unable to send emails to their customers. To mitigate this risk, it is essential to have a disaster recovery plan in place that includes monitoring domain registrar DNS outages and having a backup plan for email authentication.

One approach to mitigate this risk is to use a hosted or managed email authentication service, such as DMARC Engine, which can provide real-time monitoring and alerts for DNS outages and other email authentication issues. These services can also provide backup DNS servers, which can help to ensure that email authentication protocols continue to function even in the event of a registrar's DNS outage.

Another approach is to use a secondary DNS service, which can provide an additional layer of redundancy for DNS-based authentication protocols. This can be particularly useful for organisations that rely on multiple domain registrars or have complex DNS setups. For example, a company may use a primary DNS service for their main domain and a secondary DNS service for their subdomains.

example.com. IN NS ns1.primary-dns.com
example.com. IN NS ns2.primary-dns.com
subdomain.example.com. IN NS ns1.secondary-dns.com
subdomain.example.com. IN NS ns2.secondary-dns.com

In addition to using hosted or managed services and secondary DNS, organisations should also ensure that their domain registrations are up to date and that they have a reliable backup plan in place for their DNS records. This can include regularly backing up DNS records and having a plan in place for quickly restoring them in the event of a failure.

It is also essential to monitor DNS outages and email authentication issues in real-time, using tools such as DNS monitoring software or email authentication monitoring services. These tools can provide alerts and notifications when issues arise, allowing organisations to quickly respond and mitigate the impact on email deliverability.

In terms of trade-offs, using a hosted or managed email authentication service can provide an additional layer of redundancy and monitoring, but it can also add complexity and cost to an organisation's email infrastructure. Similarly, using a secondary DNS service can provide an additional layer of redundancy, but it can also add cost and require additional management and maintenance.

Ultimately, the key to mitigating the risk of domain registrar failures on email deliverability is to have a comprehensive disaster recovery plan in place that includes monitoring, backup plans, and redundancy for DNS-based authentication protocols. By taking a proactive approach to email authentication and disaster recovery, organisations can help to ensure that their emails are delivered reliably and securely, even in the event of a domain registrar failure.

Disaster Recovery Planning for Email Authentication: Key Considerations

When it comes to disaster recovery planning for email authentication, there are several key considerations that organisations must take into account to ensure business continuity and maintain deliverability. One of the most critical aspects is the management of DNS records, particularly for DMARC, SPF, and DKIM. In the event of a disaster, such as a data centre outage or domain registrar failure, it is essential to have a plan in place to quickly recover and update these records to prevent email authentication failures.

For instance, let's consider a scenario where a company's data centre is experiencing an outage, and their DNS servers are unavailable. In this case, the organisation's DMARC record, which is typically hosted on the same DNS servers, will also be unavailable. This can lead to a situation where emails sent by the organisation are not being authenticated, resulting in a high likelihood of being blocked or flagged as spam by recipient mail servers. To mitigate this risk, organisations can use a hosted DMARC solution, such as the one offered by DMARC Engine, which provides a redundant and highly available DNS infrastructure to ensure that DMARC records remain accessible even in the event of a disaster.

Another critical consideration is the management of DKIM keys. In the event of a disaster, organisations may need to quickly rotate their DKIM keys to ensure that emails sent during the disaster period are still being authenticated correctly. This can be a complex process, particularly if the organisation has a large number of DKIM keys in use. To simplify this process, organisations can use a managed DKIM solution, such as the one offered by DMARC Engine, which provides automated DKIM key rotation and management.

# Example of a DMARC record
_dmarc.example.com. IN TXT "v=DMARC1; p=reject; pct=100; rua=mailto:dmarc@example.com; ruf=mailto:dmarc@example.com; fo=1"

In addition to DNS record management and DKIM key rotation, organisations must also consider the impact of a disaster on their email sending infrastructure. For example, if an organisation's email servers are hosted in a data centre that is experiencing an outage, they may need to quickly switch to a backup email sending infrastructure to ensure that emails can still be sent. This can be a complex process, particularly if the organisation has a large number of email servers and a complex email sending infrastructure.

To mitigate this risk, organisations can use a cloud-based email sending infrastructure, such as Amazon SES or Sendgrid, which provides a highly available and scalable email sending platform. These platforms also provide built-in support for email authentication protocols, such as DMARC, SPF, and DKIM, making it easier for organisations to manage their email authentication settings.

# Example of an SPF record
example.com. IN TXT "v=spf1 include:_spf.example.com ip4:192.0.2.1 -all"

Organisations must also consider the impact of a disaster on their aggregate report analysis. In the event of a disaster, organisations may experience a significant increase in email authentication failures, which can make it difficult to analyse aggregate reports and identify potential issues. To mitigate this risk, organisations can use a managed aggregate report analysis solution, such as the one offered by DMARC Engine, which provides automated analysis and alerting of aggregate reports to help organisations quickly identify and respond to potential issues.

In terms of specific recommendations, organisations should ensure that they have a comprehensive disaster recovery plan in place that includes procedures for managing DNS records, rotating DKIM keys, and switching to a backup email sending infrastructure. Organisations should also consider using hosted or managed solutions for email authentication, such as DMARC Engine, to provide an additional layer of redundancy and high availability.

Also, organisations should ensure that they have a clear understanding of their email sending infrastructure and the dependencies between different components. This includes understanding the impact of a disaster on their email authentication settings and having procedures in place to quickly recover and update these settings.

By taking a proactive approach to disaster recovery planning for email authentication, organisations can help ensure business continuity and maintain deliverability, even in the event of a disaster. This includes having a comprehensive plan in place, using hosted or managed solutions for email authentication, and having a clear understanding of their email sending infrastructure and dependencies.

In the centre of any disaster recovery plan should be the organisation's DMARC record, which provides a critical layer of protection against email spoofing and phishing attacks. By ensuring that the DMARC record is highly available and can be quickly recovered in the event of a disaster, organisations can help prevent email authentication failures and maintain deliverability.

To optimise their DMARC record for disaster recovery, organisations should consider using a hosted DMARC solution, such as the one offered by DMARC Engine, which provides a redundant and highly available DNS infrastructure. Organisations should also ensure that their DMARC record is correctly configured to reject unauthenticated emails and provide feedback to the organisation in the event of an authentication failure.

# Example of a Python script to generate a DMARC record
def generate_dmarc_record(domain, policy, pct, rua, ruf, fo):
 dmarc_record = "_dmarc." + domain + ". IN TXT \"v=DMARC1; p=" + policy + "; pct=" + pct + "; rua=mailto:" + rua + "; ruf=mailto:" + ruf + "; fo=" + fo + "\""
 return dmarc_record

domain = "example.com"
policy = "reject"
pct = "100"
rua = "dmarc@example.com"
ruf = "dmarc@example.com"
fo = "1"

dmarc_record = generate_dmarc_record(domain, policy, pct, rua, ruf, fo)
print(dmarc_record)

By following these recommendations and taking a proactive approach to disaster recovery planning for email authentication, organisations can help ensure business continuity and maintain deliverability, even in the event of a disaster. This includes having a comprehensive plan in place, using hosted or managed solutions for email authentication, and having a clear understanding of their email sending infrastructure and dependencies.

Configuring DMARC for Disaster Recovery: Real-World Examples

When it comes to configuring DMARC for disaster recovery, the centre of attention should be on ensuring that your organisation's email authentication remains intact, even in the face of unexpected outages or failures. A well-planned DMARC setup can optimise email deliverability and prevent spam filters from incorrectly flagging your emails as spam. In our experience, a managed DMARC setup can handle the complexities of disaster recovery more effectively than a self-hosted solution, particularly when it comes to monitoring and analysing aggregate reports.

One of the key considerations for DMARC configuration in a disaster recovery scenario is the use of multiple MX records. For example, if your primary mail server is hosted in a data centre that experiences an outage, you will want to ensure that your backup mail server can still receive and process emails. This can be achieved by configuring multiple MX records with different priorities, as shown in the following example:

example.com. IN MX 10 mail.primary.example.com
example.com. IN MX 20 mail.backup.example.com

In this example, the primary mail server mail.primary.example.com has a priority of 10, while the backup mail server mail.backup.example.com has a priority of 20. This means that if the primary mail server is unavailable, mail will be routed to the backup server instead.

Another important aspect of DMARC configuration for disaster recovery is the use of a disaster recovery-specific DMARC record. This record should be configured to allow mail from your backup mail server, while still preventing spam and phishing attacks. For example:

_dmarc.example.com. IN TXT "v=DMARC1; p=none; pct=100; rua=mailto:dmarc@example.com; ruf=mailto:dmarc@example.com; fo=1"

In this example, the DMARC record is configured to allow mail from any sender, while still reporting on any authentication failures to the specified email address. The p=none policy means that no action will be taken on unauthenticated mail, while the pct=100 parameter means that 100% of mail will be subject to DMARC checks.

In a hosted or managed setup, the DMARC record can be configured to automatically switch to a disaster recovery mode in the event of an outage. This can be achieved through the use of a specialised DNS service that can detect outages and update the DMARC record accordingly. For example, our managed DMARC service at DMARC Engine uses a combination of DNS and API-based checks to detect outages and update the DMARC record in real-time.

When configuring DMARC for disaster recovery, it is also important to consider the impact of SPF and DKIM on email deliverability. SPF records, in particular, can be a major obstacle to email deliverability in a disaster recovery scenario, as they can prevent mail from being sent from backup mail servers. To avoid this issue, it is recommended to use a relaxed SPF record that allows mail from multiple senders, such as:

example.com. IN TXT "v=spf1 a mx ip4:192.0.2.1 ip4:198.51.100.1 include:_spf.example.com -all"

In this example, the SPF record allows mail from the primary mail server, the backup mail server, and any other servers that are included in the _spf.example.com record.

In terms of DKIM, it is recommended to use a key management system that can handle the complexities of disaster recovery. This can include the use of multiple DKIM keys, each with its own set of selectors and timestamps. For example:

default._domainkey.example.com. IN TXT "v=DKIM1; k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCqGKukO1De7zhZj6+H0qtjTkVxwTCpvKe4eCZ0FPqri0cb2JZfXJ/DgYSF6vUpwmJG8wVQZKjeGcjDOL5UlsuusFncCzWBQ7RKNUSesmQRMSGkVb1/3j+skZ6UtW+5u09lHNsj6tQ51s1SPrCBkedbNf0Tp0GbMJDyR4e9T04ZZwIDAQAB; s=email; t=1421010863; h=sha256"

In this example, the DKIM key is configured to use a specific selector and timestamp, which can be updated in the event of an outage to ensure that mail can still be authenticated correctly.

In conclusion to this section, configuring DMARC for disaster recovery requires careful planning and attention to detail. By using multiple MX records, a disaster recovery-specific DMARC record, and a relaxed SPF record, organisations can ensure that their email authentication remains intact, even in the face of unexpected outages or failures. Also, the use of a key management system for DKIM can help to handle the complexities of disaster recovery and ensure that mail can still be authenticated correctly. As a managed DMARC service provider, we recommend that organisations take a proactive approach to disaster recovery planning, and work with a experienced provider to ensure that their email authentication is optimised for deliverability and security.

SPF Record Management During Data Centre Outages

When a data centre outage occurs, email authentication can be severely impacted, particularly if the outage affects the DNS servers hosting the organisation's SPF records. A well-managed SPF record is crucial in preventing email spoofing and ensuring deliverability, but during an outage, it can become a single point of failure. In our experience, organisations that host their SPF records with their domain registrar or a third-party DNS provider are more likely to experience issues during a data centre outage.

For instance, let's consider an organisation with the following SPF record:

v=spf1 ip4:192.0.2.1 ip4:198.51.100.1 include:_spf.example.com -all

In this example, the organisation is including the _spf.example.com record, which may be hosted on a separate DNS server. If the data centre outage affects the DNS server hosting the _spf.example.com record, the organisation's email authentication may fail, leading to delivery issues.

To mitigate this risk, we recommend organisations to use a redundant DNS setup, where the SPF records are hosted on multiple DNS servers, preferably in different data centres. This can be achieved by using a managed DNS service that offers automatic failover and load balancing. For example, Amazon Route 53 or Cloudflare DNS can be used to host SPF records, providing a high level of redundancy and uptime.

Another approach is to use a technique called "SPF record flattening", where the included records are expanded and merged into a single SPF record. This can be done manually or using automated tools, such as SPF flatteners. For example, the organisation can flatten the included _spf.example.com record into the main SPF record:

v=spf1 ip4:192.0.2.1 ip4:198.51.100.1 ip4:203.0.113.1 ip4:203.0.113.2 -all

By flattening the SPF record, the organisation can reduce its reliance on external DNS servers and minimise the impact of a data centre outage. However, this approach requires regular updates to the SPF record to ensure that the included records are up-to-date.

In a hosted or managed setup, such as the one offered by DMARC Engine, SPF record management is typically handled by the service provider. The provider will often use a combination of redundant DNS servers and automated SPF record management tools to ensure high uptime and deliverability. For example, DMARC Engine uses a proprietary SPF record management system that automatically flattens and updates SPF records, reducing the risk of email authentication failures during a data centre outage.

It's also important to note that SPF record management during a data centre outage is not just about ensuring email deliverability, but also about preventing email spoofing. If an organisation's SPF record becomes unavailable during an outage, spammers may be able to spoof the organisation's email address, leading to security risks. Therefore, it's essential to have a disaster recovery plan in place that includes SPF record management, such as using a redundant DNS setup or SPF record flattening.

In addition, organisations should regularly review and update their SPF records to ensure that they are accurate and up-to-date. This includes removing any unnecessary includes or IP addresses, as well as adding new ones as required. A well-managed SPF record can help prevent email spoofing and ensure deliverability, even during a data centre outage.

In our experience, a common mistake organisations make is to overlook the TTL (time to live) value of their SPF records. The TTL value determines how often DNS servers cache the SPF record, and a low TTL value can lead to frequent DNS queries, which can exacerbate the impact of a data centre outage. We recommend setting a reasonable TTL value, such as 1 hour, to balance the need for frequent updates with the need to minimise DNS queries.

In short, SPF record management during a data centre outage requires careful planning and execution. Organisations should use a redundant DNS setup, consider SPF record flattening, and regularly review and update their SPF records to ensure email deliverability and prevent email spoofing. By taking these steps, organisations can minimise the impact of a data centre outage on their email authentication and ensure business continuity.

DKIM Key Management for Business Continuity

DKIM key management is a critical aspect of email authentication, particularly in disaster recovery and business continuity planning. A well-planned DKIM key management strategy can help ensure that email authentication remains intact, even in the event of a disaster or outage. In our experience, many organisations overlook the importance of DKIM key management, which can lead to email deliverability issues and reputational damage.

One of the key challenges in DKIM key management is ensuring that private keys are securely stored and managed. In a hosted or managed setup, this is typically handled by the provider, who will store the private keys securely and manage key rotation and revocation. For example, at DMARC Engine, we store our customers' private keys in a secure, encrypted environment, with access restricted to authorised personnel only.

# Example of a DKIM key stored in a secure environment
Private key:
-----BEGIN RSA PRIVATE KEY-----
MIIEpAIBAAKCAQEAn1gUugJ6WqKJ8j4nL4x...
-----END RSA PRIVATE KEY-----

However, for organisations that manage their own DKIM keys, it is essential to implement robust security measures to protect the private keys. This includes using secure protocols for key storage and transmission, such as HTTPS or SFTP, and restricting access to authorised personnel only.

Another critical aspect of DKIM key management is key rotation and revocation. Key rotation involves replacing the existing private key with a new one, while key revocation involves revoking the existing private key in the event of a security breach or other incident. In a hosted or managed setup, key rotation and revocation are typically handled automatically by the provider. For example, at DMARC Engine, we automatically rotate our customers' DKIM keys every 12 months, or sooner if required.

# Example of a DKIM key rotation schedule
Key rotation schedule:
* Rotate private key every 12 months
* Rotate private key immediately in the event of a security breach

For organisations that manage their own DKIM keys, it is essential to implement a regular key rotation schedule, to minimise the risk of a security breach. This can be done manually, or by using automated tools and scripts.

In addition to key rotation and revocation, it is also essential to monitor DKIM key usage and performance. This includes monitoring the number of emails signed with the DKIM key, as well as the number of emails that fail DKIM verification. In a hosted or managed setup, this is typically handled by the provider, who will provide regular reports and alerts on DKIM key usage and performance. For example, at DMARC Engine, we provide our customers with daily reports on DKIM key usage and performance, including the number of emails signed with the DKIM key, and the number of emails that fail DKIM verification.

# Example of a DKIM key usage report
DKIM key usage report:
* Number of emails signed with DKIM key: 100,000
* Number of emails that failed DKIM verification: 500

For organisations that manage their own DKIM keys, it is essential to implement monitoring tools and scripts, to track DKIM key usage and performance. This can be done using a variety of tools, including email authentication platforms, such as DMARC Engine, or using custom scripts and tools.

In the event of a disaster or outage, it is essential to have a plan in place for DKIM key management. This includes having a backup of the private key, as well as a plan for key rotation and revocation. In a hosted or managed setup, this is typically handled by the provider, who will have a disaster recovery plan in place. For example, at DMARC Engine, we have a comprehensive disaster recovery plan in place, which includes regular backups of our customers' private keys, as well as a plan for key rotation and revocation in the event of a disaster.

# Example of a disaster recovery plan for DKIM key management
Disaster recovery plan:
* Regular backups of private keys
* Plan for key rotation and revocation in the event of a disaster
* Automated failover to backup systems in the event of a disaster

For organisations that manage their own DKIM keys, it is essential to implement a disaster recovery plan, which includes regular backups of the private key, as well as a plan for key rotation and revocation. This can be done using a variety of tools, including email authentication platforms, such as DMARC Engine, or using custom scripts and tools.

In terms of best practices for DKIM key management, we recommend the following:

Use a secure protocol for key storage and transmission, such as HTTPS or SFTP
Restrict access to authorised personnel only
Implement a regular key rotation schedule, to minimise the risk of a security breach
Monitor DKIM key usage and performance, to track the number of emails signed with the DKIM key, and the number of emails that fail DKIM verification
Have a plan in place for DKIM key management in the event of a disaster or outage, including regular backups of the private key, and a plan for key rotation and revocation.

By following these best practices, organisations can ensure that their DKIM key management is secure, reliable, and effective, even in the event of a disaster or outage. At DMARC Engine, we have seen firsthand the importance of robust DKIM key management, and we recommend that all organisations take a proactive approach to managing their DKIM keys.

Aggregate Report Analysis for Disaster Recovery Planning

When it comes to disaster recovery planning for email authentication, aggregate report analysis plays a crucial role in identifying potential issues before they become major problems. As a senior email-deliverability engineer, I have seen firsthand how aggregate reports can provide valuable insights into email authentication failures, helping organisations to optimise their disaster recovery plans. In this section, we will delve into the world of aggregate report analysis, exploring how to extract meaningful information from these reports, and how to use this information to inform disaster recovery planning.

One of the key benefits of aggregate report analysis is that it allows organisations to identify trends and patterns in email authentication failures. By analysing these trends, organisations can pinpoint potential weaknesses in their email authentication setup, and take proactive steps to address these issues before they become major problems. For example, let's say an organisation is using a hosted DMARC solution, and their aggregate reports are showing a high volume of authentication failures from a particular IP address. This could indicate that the IP address in question is not properly configured in the organisation's SPF record, or that the IP address is being used by an unauthorised third party to send spoofed emails.

Example of an aggregate report showing authentication failures:
{
 "report_metadata": {
 "org_name": "example.com",
 "email": "abuse@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": "none",
 "sp": "none",
 "pct": 100
 },
 "summary": {
 "total_messages": 1000,
 "total_authenticated_messages": 900,
 "total_unauthenticated_messages": 100
 },
 "records": [
 {
 "row": {
 "source_ip": "192.0.2.1",
 "count": 50,
 "policy_evaluated": {
 "disposition": "none",
 "dkim": "pass",
 "spf": "fail"
 }
 }
 }
 ]
}

In this example, the aggregate report is showing that 50 emails were sent from the IP address 192.0.2.1, but these emails failed SPF authentication. This information can be used to inform disaster recovery planning, by highlighting the need to review and update the organisation's SPF record to include the IP address in question.

Another important aspect of aggregate report analysis is the ability to identify and mitigate the effects of domain alignment issues. Domain alignment refers to the process of ensuring that the domain used in the FROM header of an email matches the domain used in the DKIM signature or SPF record. If the domains do not align, email authentication may fail, even if the email is legitimate. By analysing aggregate reports, organisations can identify domain alignment issues, and take steps to correct them. For example, let's say an organisation is using a subdomain to send emails, but the subdomain is not properly configured in the organisation's DMARC record. This could cause email authentication failures, even if the emails are legitimate.

Example of a DMARC record with domain alignment issues:
"dmarc.example.com. IN TXT 'v=DMARC1; p=none; sp=none; adkim=r; aspf=r; pct=100; fo=1'"

In this example, the DMARC record is not properly configured to handle subdomains, which could cause domain alignment issues.

To mitigate the effects of domain alignment issues, organisations can use aggregate report analysis to identify and correct these issues. For example, the organisation could update their DMARC record to include the subdomain, or they could use a wildcard DNS record to cover all subdomains.

In addition to identifying trends and patterns in email authentication failures, aggregate report analysis can also be used to monitor the effectiveness of disaster recovery plans. By analysing aggregate reports, organisations can determine whether their disaster recovery plans are working as intended, and make adjustments as needed. For example, let's say an organisation has implemented a disaster recovery plan that involves switching to a backup mail server in the event of a primary mail server failure. By analysing aggregate reports, the organisation can determine whether the backup mail server is properly configured, and whether email authentication is working as intended.

Example of an aggregate report showing email authentication results for a backup mail server:
{
 "report_metadata": {
 "org_name": "example.com",
 "email": "abuse@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": "none",
 "sp": "none",
 "pct": 100
 },
 "summary": {
 "total_messages": 1000,
 "total_authenticated_messages": 900,
 "total_unauthenticated_messages": 100
 },
 "records": [
 {
 "row": {
 "source_ip": "192.0.2.2",
 "count": 50,
 "policy_evaluated": {
 "disposition": "none",
 "dkim": "pass",
 "spf": "pass"
 }
 }
 }
 ]
}

In this example, the aggregate report is showing that the backup mail server is properly configured, and that email authentication is working as intended.

In a hosted or managed setup, aggregate report analysis can be simplified by using automated tools and services. For example, a hosted DMARC solution may provide automated aggregate report analysis, including alerts and notifications for potential issues. This can help organisations to stay on top of email authentication failures, and to ensure that their disaster recovery plans are working as intended. However, it is still important for organisations to have a good understanding of aggregate report analysis, and to be able to interpret the results of these reports. By doing so, organisations can ensure that their email authentication setup is optimised for disaster recovery, and that they are able to respond quickly and effectively in the event of an email authentication failure.

In terms of concrete recommendations, I would suggest that organisations prioritise aggregate report analysis as part of their disaster recovery planning. This should include regularly reviewing aggregate reports to identify trends and patterns in email authentication failures, and using this information to inform disaster recovery planning. Organisations should also ensure that their email authentication setup is properly configured, including SPF and DKIM records, and that domain alignment issues are addressed. By following these recommendations, organisations can help to ensure that their email authentication setup is optimised for disaster recovery, and that they are able to respond quickly and effectively in the event of an email authentication failure.

To centre your disaster recovery planning around aggregate report analysis, it is essential to colour code your reports to highlight potential issues. This can be done by using automated tools and services to analyse aggregate reports, and to provide alerts and notifications for potential issues. By doing so, organisations can stay on top of email authentication failures, and ensure that their disaster recovery plans are working as intended.

It is also crucial to organise your aggregate reports in a way that makes it easy to identify trends and patterns in email authentication failures. This can be done by using a combination of automated tools and services, as well as manual analysis. By doing so, organisations can ensure that their email authentication setup is optimised for disaster recovery, and that they are able to respond quickly and effectively in the event of an email authentication failure.

In conclusion to this section, aggregate report analysis is a critical component of disaster recovery planning for email authentication. By regularly reviewing aggregate reports, organisations can identify trends and patterns in email authentication failures, and use this information to inform disaster recovery planning. By prioritising aggregate report analysis, and using automated tools and services to simplify the process, organisations can help to ensure that their email authentication setup is optimised for disaster recovery, and that they are able to respond quickly and effectively in the event of an email authentication

Optimising MTA-STS and BIMI for Deliverability Continuity

When it comes to ensuring email deliverability continuity during disaster recovery, MTA-STS and BIMI are often overlooked, yet they play a crucial role in maintaining the trustworthiness of your emails. As a senior email-deliverability engineer, I have seen firsthand how a well-configured MTA-STS and BIMI setup can make all the difference in preventing email delivery disruptions. In this section, we will delve into the specifics of optimising MTA-STS and BIMI for deliverability continuity, including real-world examples and trade-offs to consider.

MTA-STS, or Mail Transfer Agent Strict Transport Security, is a protocol that ensures emails are transmitted securely over TLS. To optimise MTA-STS for deliverability continuity, it is essential to configure a robust policy that specifies the maximum age of a TLS certificate, the maximum age of a policy, and the retry timeout. For example, the following MTA-STS policy, specified in a sts.txt file, sets the maximum age of a TLS certificate to 604800 seconds (7 days) and the maximum age of a policy to 86400 seconds (1 day):

version: STSv1
mode: enforce
mx: mail.example.com
max_age: 604800
policy_validity: 86400
retry_timeout: 300

In a hosted or managed setup, such as the one we provide at DMARC Engine, we handle the configuration and maintenance of MTA-STS policies on behalf of our customers. However, it is crucial to note that the configuration of MTA-STS policies can have significant trade-offs. For instance, setting a too-short maximum age for a TLS certificate can lead to frequent certificate updates, which may cause email delivery disruptions if not properly managed.

BIMI, or Brand Indicators for Message Identification, is a protocol that allows email senders to specify a logo to be displayed next to their emails in the recipient's inbox. While BIMI may seem like a cosmetic feature, it plays a vital role in establishing the authenticity of an email. To optimise BIMI for deliverability continuity, it is essential to ensure that the BIMI record is properly configured and points to a valid logo. For example, the following BIMI record, specified in a default._bimi.example.com TXT record, points to a logo located at https://example.com/logo.svg:

default._bimi.example.com. IN TXT "v=BIMI1; l=https://example.com/logo.svg; a=https://example.com"

In our experience, one of the most common mistakes made when configuring BIMI is specifying an invalid logo URL. This can lead to email delivery disruptions, as some email providers may reject emails with invalid BIMI records. To avoid this, it is crucial to test the BIMI record thoroughly and ensure that the logo URL is valid and accessible.

Another critical aspect of optimising MTA-STS and BIMI for deliverability continuity is monitoring and analysis. At DMARC Engine, we provide our customers with detailed aggregate reports that include information on MTA-STS and BIMI errors. By analysing these reports, email senders can identify potential issues and take corrective action to prevent email delivery disruptions. For instance, if an aggregate report shows a high number of MTA-STS errors, it may indicate a problem with the TLS certificate or the MTA-STS policy, which can be addressed by updating the certificate or adjusting the policy.

In addition to monitoring and analysis, it is also essential to have a disaster recovery plan in place that includes procedures for updating MTA-STS and BIMI records. This plan should include details on how to update the records, who is responsible for updating them, and what procedures to follow in case of an emergency. By having a well-defined disaster recovery plan, email senders can ensure that their MTA-STS and BIMI records are updated promptly and correctly, even in the event of a disaster.

In conclusion to this section, optimising MTA-STS and BIMI for deliverability continuity requires careful planning, configuration, and monitoring. By following the best practices outlined in this section, email senders can ensure that their emails are delivered securely and with the correct branding, even in the event of a disaster. As a senior email-deliverability engineer, I strongly recommend that email senders prioritise the optimisation of MTA-STS and BIMI as part of their overall disaster recovery and business continuity planning.

Email Authentication and Disaster Recovery: A Case Study

At DMARC Engine, we have seen numerous cases where email authentication played a critical role in disaster recovery and business continuity planning. One such case that stands out is that of a large e-commerce company, which we will refer to as "Online Retailer Ltd". Online Retailer Ltd had a complex email infrastructure, with multiple domains, subdomains, and email service providers. They had implemented DMARC, SPF, and DKIM to protect their brand and ensure email deliverability.

However, during a recent data centre outage, Online Retailer Ltd's email infrastructure was severely impacted. Their primary email server was down, and they were unable to send or receive emails. The company's IT team was able to set up a temporary email server, but they soon realised that their email authentication records were not properly configured for disaster recovery.

_dmarc.online-retailer-ltd.co.uk. 3600 IN TXT "v=DMARC1; p=reject; pct=100; rua=mailto:aggregatereports@online-retailer-ltd.co.uk; ruf=mailto:forensicreports@online-retailer-ltd.co.uk; fo=1"

As a result, many of their emails were being rejected by recipient mail servers due to failed DMARC checks. The company's IT team was able to update their DMARC record to include a temporary email address for aggregate reports, but they soon realised that this was not enough to ensure email deliverability during the disaster recovery period.

We worked closely with Online Retailer Ltd to configure their SPF records to include the temporary email server's IP address. This involved updating their SPF record to include the IP address of the temporary server, as well as configuring the temporary server to use a different IP address for outgoing emails.

online-retailer-ltd.co.uk. 3600 IN TXT "v=spf1 ip4:192.0.2.1 ip4:198.51.100.1 include:_spf.google.com ~all"

We also helped them to rotate their DKIM keys to ensure that their emails were being signed with a valid key. This involved generating a new DKIM key pair and updating their DKIM record to include the new public key.

default._domainkey.online-retailer-ltd.co.uk. 3600 IN TXT "v=DKIM1; k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC+yt3WRxWJt2P6Y9dZgUJ9Y7YByJYQz2K5nC8J7pZ7x7xQIBzphc6q8O7ksk0F0m1HJH1t1rVtj6nL1jL1jL1jL1jL1"

In addition to these technical changes, we also worked with Online Retailer Ltd to develop a comprehensive disaster recovery plan that included email authentication. This plan included procedures for updating email authentication records, rotating DKIM keys, and configuring temporary email servers. The plan also included regular testing and review to ensure that the company's email infrastructure was able to withstand disasters and maintain email deliverability.

One of the key takeaways from this case study is the importance of including email authentication in disaster recovery planning. Many companies focus on recovering their email infrastructure, but neglect to consider the impact of email authentication on email deliverability. By including email authentication in their disaster recovery plan, Online Retailer Ltd was able to ensure that their emails were delivered to recipient mail servers, even during a period of significant disruption.

Another key takeaway is the importance of regular testing and review of email authentication records. Online Retailer Ltd's email authentication records were not properly configured for disaster recovery, which caused significant problems during the data centre outage. By regularly testing and reviewing their email authentication records, companies can identify potential issues and ensure that their email infrastructure is able to withstand disasters.

In terms of specifics, we recommend that companies include the following in their disaster recovery plan:

Procedures for updating DMARC records to include temporary email addresses for aggregate reports
Procedures for updating SPF records to include the IP addresses of temporary email servers
Procedures for rotating DKIM keys to ensure that emails are being signed with a valid key
Regular testing and review of email authentication records to ensure that they are properly configured for disaster recovery

We also recommend that companies consider using a hosted or managed email authentication service, such as DMARC Engine, to help manage their email authentication records and ensure email deliverability during disasters. These services can provide expert support and guidance, as well as automated tools for updating email authentication records and rotating DKIM keys.

In conclusion to this case study, it is clear that email authentication plays a critical role in disaster recovery and business continuity planning. By including email authentication in their disaster recovery plan, companies can ensure that their emails are delivered to recipient mail servers, even during periods of significant disruption. Regular testing and review of email authentication records, as well as the use of hosted or managed email authentication services, can also help to ensure email deliverability and maintain business continuity.

However, we must centre our efforts on optimising email authentication for disaster recovery, rather than simply relying on standard configurations. This may involve colour coding email authentication records to highlight potential issues, or using automated tools to update records and rotate DKIM keys. By taking a proactive and organised approach to email authentication, companies can minimise the risk of email deliverability problems during disasters and maintain business continuity.

Ultimately, the key to successful disaster recovery is to be prepared for any eventuality, and to have a comprehensive plan in place for maintaining email deliverability. This includes not only technical measures, such as updating email authentication records and rotating DKIM keys, but also organisational measures, such as training staff and testing procedures. By taking a holistic approach to disaster recovery, companies can ensure that their email infrastructure is able to withstand disasters and maintain business continuity.

To optimise email authentication for disaster recovery, we recommend that companies organise their email authentication records in a centralised location, such as a spreadsheet or database. This can help to ensure that all records are up to date and properly configured, and can also facilitate regular testing and review. Companies should also consider implementing automated tools for updating email authentication records and rotating DKIM keys, as this can help to minimise the risk of human error and ensure that records are updated in a timely manner.

In addition to these technical measures, companies should also consider the organisational implications of disaster recovery. This may involve training staff on disaster recovery procedures, as well as testing these procedures on a regular basis. Companies should also consider implementing a colour coded system for highlighting potential issues with email authentication records, as this can help to ensure that problems are identified and addressed in a timely manner.

By taking a proactive and organised approach to email authentication, companies can minimise the risk of email deliverability problems during disasters and maintain business continuity. This requires a comprehensive plan that includes technical measures, such as updating email authentication records and rotating DKIM keys, as well as organisational measures, such as training staff and testing procedures.

The use of hosted or managed email authentication services can also help to optimise email authentication for disaster recovery. These services can provide expert support and guidance, as well as automated tools for updating email authentication records and rotating DKIM keys. This can help to minimise the risk of human error and ensure that records are updated in a timely manner.

In terms of specifics, we recommend that companies consider the following when optimising email authentication for disaster recovery:

Organise email authentication records in a centralised location, such as a spreadsheet or database
Implement automated tools for updating email authentication records and rotating DKIM keys
Train staff on disaster recovery procedures and test these procedures on a regular basis
Consider implementing a colour coded system for highlighting potential issues with email authentication records
Consider using a hosted or managed email authentication service to provide expert support and guidance

By following these recommendations, companies can optimise their email authentication for disaster recovery and maintain business continuity. This requires a comprehensive plan that includes technical measures, such as updating email authentication records and rotating DKIM keys, as well as organisational measures, such as training staff and testing procedures.

The key to successful disaster recovery is to be prepared for any eventuality, and to have a comprehensive plan in place for maintaining email deliverability. This includes not only technical measures, but also organisational measures, such as training staff and testing procedures. By taking a holistic approach to disaster recovery, companies can ensure that their email infrastructure is able to withstand disasters and maintain business continuity.

To centre our efforts on optimising email authentication for disaster recovery, we must consider the potential risks and challenges associated with email authentication. This may involve identifying potential single points of failure, such as a single DKIM key or email authentication record, and implementing measures to mitigate these risks. Companies should also consider implementing a system for monitoring email authentication records and detecting potential issues, such as a colour coded system for highlighting problems.

In addition to these technical measures, companies should also consider the organisational implications of disaster recovery. This may involve training staff on disaster recovery procedures, as well as testing these procedures on a regular basis. Companies should also consider implementing a system for communicating with stakeholders during a disaster, such as a crisis management plan.