DKIM & DMARC: Beyond Elementary Email

Email: we may love it, hate it, or fall somewhere in between, but we all know it. The opaque system of servers, addresses, and distribution groups enables the familiar game of corporate tag around which so much of our life depends. I can’t tell you how many tickets I’ve dealt with concerning email: some have and can’t access it, others need it and don’t have it yet. Some have lost emails they need to find, and others have emails they are unsure if they need to lose. I’ve traversed spam filters and message traces, pored over headers and message IDs till my eyes water, and configured enough email clients to last a lifetime. But, for every email ticket I do that I’ve done before, I do a couple that are new.

Information technology is constantly changing and evolving, especially in security. Email infrastructure is no exception. Those whose livelihoods involve assessing cyber threats estimate that 90% or more of hacks begin with successful phishing emails. That’s why email authentication is so important, which is how emails prove that they have not been spoofed or tampered with. DMARC Domain-based Message Authentication, Reporting & Conformance (DMARC) is an email authentication protocol designed to give domain owners the ability to protect their domain from unauthorized use, commonly known as email spoofing. By implementing DMARC, domain owners can specify that their emails are protected by both SPF (Sender Policy Framework) and DKIM (DomainKeys Identified Mail) protocols, significantly reducing the risk of email fraud and phishing attacks. Key components and benefits of DMARC include: Authentication: DMARC builds on SPF and DKIM authentication mechanisms by ensuring that the sender's email domain aligns with the domain in the email's From header. This alignment helps verify the authenticity of the email sender. Policy Enforcement: Domain owners can set policies on how to handle unauthenticated emails. These policies can include monitoring only, quarantine (moving emails to spam), or rejecting unauthenticated emails outright. Reporting: DMARC provides domain owners with valuable feedback through aggregate and forensic reports. Aggregate reports show summary data on email authentication failures, while forensic reports provide detailed information on individual emails that fail DMARC checks, aiding in the identification and mitigation of potential phishing attempts. Visibility: By aggregating data from recipient email servers, DMARC offers domain owners insight into who is sending emails on behalf of their domain, enabling them to detect and take action against malicious activities. Improved Email Deliverability: Authenticating emails with DMARC can enhance overall email deliverability rates, as receiving servers are more likely to trust and accept emails from authenticated sources. Implementing DMARC is a critical step in securing email communications and protecting an organization's brand reputation. By combining DMARC with SPF and DKIM, domain owners can establish a robust defense against email-based threats, contributing to a safer and more trustworthy email ecosystem. and DKIM DomainKeys Identified Mail (DKIM) is an email authentication method that allows the recipient to verify that an email was indeed sent and authorized by the owner of that domain. This is achieved through the use of cryptographic signatures, which are added to the email headers. When the email is received, the recipient's mail server uses the domain's public key, which is published in the DNS, to verify the signature. This ensures that the email has not been altered or forged in transit. Key features and benefits of DKIM include: Email Integrity: DKIM helps verify that the email content has not been tampered with during transmission, ensuring that it arrives in the same state in which it was sent. Authentication: By confirming that the sender's domain aligns with the domain in the DKIM signature, recipients can reliably identify the source of the email. Reputation Management: Consistently sending DKIM-signed emails can enhance the domain's reputation with email service providers, reducing the likelihood of emails being flagged as spam. Interoperability: DKIM works in conjunction with other email authentication mechanisms, such as SPF and DMARC, providing an additional layer of security. Transparency: DKIM operates in the background and does not impact the user's experience, as the verification process is transparent to the end user. Implementing DKIM helps organizations protect their email infrastructure against phishing and spoofing attacks, ensuring better trust and deliverability of their email communications. It is a crucial component of a comprehensive email security strategy when combined with SPF and DMARC. are difficult-to-pronounce (and type) acronyms that mean “methods of making your emails more secure.”

However, cyber security is not the only concern with email. DMARC Domain-based Message Authentication, Reporting & Conformance (DMARC) is an email authentication protocol designed to give domain owners the ability to protect their domain from unauthorized use, commonly known as email spoofing. By implementing DMARC, domain owners can specify that their emails are protected by both SPF (Sender Policy Framework) and DKIM (DomainKeys Identified Mail) protocols, significantly reducing the risk of email fraud and phishing attacks. Key components and benefits of DMARC include: Authentication: DMARC builds on SPF and DKIM authentication mechanisms by ensuring that the sender's email domain aligns with the domain in the email's From header. This alignment helps verify the authenticity of the email sender. Policy Enforcement: Domain owners can set policies on how to handle unauthenticated emails. These policies can include monitoring only, quarantine (moving emails to spam), or rejecting unauthenticated emails outright. Reporting: DMARC provides domain owners with valuable feedback through aggregate and forensic reports. Aggregate reports show summary data on email authentication failures, while forensic reports provide detailed information on individual emails that fail DMARC checks, aiding in the identification and mitigation of potential phishing attempts. Visibility: By aggregating data from recipient email servers, DMARC offers domain owners insight into who is sending emails on behalf of their domain, enabling them to detect and take action against malicious activities. Improved Email Deliverability: Authenticating emails with DMARC can enhance overall email deliverability rates, as receiving servers are more likely to trust and accept emails from authenticated sources. Implementing DMARC is a critical step in securing email communications and protecting an organization's brand reputation. By combining DMARC with SPF and DKIM, domain owners can establish a robust defense against email-based threats, contributing to a safer and more trustworthy email ecosystem. and DKIM DomainKeys Identified Mail (DKIM) is an email authentication method that allows the recipient to verify that an email was indeed sent and authorized by the owner of that domain. This is achieved through the use of cryptographic signatures, which are added to the email headers. When the email is received, the recipient's mail server uses the domain's public key, which is published in the DNS, to verify the signature. This ensures that the email has not been altered or forged in transit. Key features and benefits of DKIM include: Email Integrity: DKIM helps verify that the email content has not been tampered with during transmission, ensuring that it arrives in the same state in which it was sent. Authentication: By confirming that the sender's domain aligns with the domain in the DKIM signature, recipients can reliably identify the source of the email. Reputation Management: Consistently sending DKIM-signed emails can enhance the domain's reputation with email service providers, reducing the likelihood of emails being flagged as spam. Interoperability: DKIM works in conjunction with other email authentication mechanisms, such as SPF and DMARC, providing an additional layer of security. Transparency: DKIM operates in the background and does not impact the user's experience, as the verification process is transparent to the end user. Implementing DKIM helps organizations protect their email infrastructure against phishing and spoofing attacks, ensuring better trust and deliverability of their email communications. It is a crucial component of a comprehensive email security strategy when combined with SPF and DMARC. could also be described as making your emails more trustworthy: when you send mail to other companies, your emails have a better reputation and are more likely to be delivered without being blocked, quarantined, or marked as spam.

The Flyover

Let me back up a moment: any salesperson can reel off the benefits of a product without giving you any real ground to stand on concerning what it does. DKIM DomainKeys Identified Mail (DKIM) is an email authentication method that allows the recipient to verify that an email was indeed sent and authorized by the owner of that domain. This is achieved through the use of cryptographic signatures, which are added to the email headers. When the email is received, the recipient's mail server uses the domain's public key, which is published in the DNS, to verify the signature. This ensures that the email has not been altered or forged in transit. Key features and benefits of DKIM include: Email Integrity: DKIM helps verify that the email content has not been tampered with during transmission, ensuring that it arrives in the same state in which it was sent. Authentication: By confirming that the sender's domain aligns with the domain in the DKIM signature, recipients can reliably identify the source of the email. Reputation Management: Consistently sending DKIM-signed emails can enhance the domain's reputation with email service providers, reducing the likelihood of emails being flagged as spam. Interoperability: DKIM works in conjunction with other email authentication mechanisms, such as SPF and DMARC, providing an additional layer of security. Transparency: DKIM operates in the background and does not impact the user's experience, as the verification process is transparent to the end user. Implementing DKIM helps organizations protect their email infrastructure against phishing and spoofing attacks, ensuring better trust and deliverability of their email communications. It is a crucial component of a comprehensive email security strategy when combined with SPF and DMARC. stands for Domain Keys Identified Mail, while DMARC Domain-based Message Authentication, Reporting & Conformance (DMARC) is an email authentication protocol designed to give domain owners the ability to protect their domain from unauthorized use, commonly known as email spoofing. By implementing DMARC, domain owners can specify that their emails are protected by both SPF (Sender Policy Framework) and DKIM (DomainKeys Identified Mail) protocols, significantly reducing the risk of email fraud and phishing attacks. Key components and benefits of DMARC include: Authentication: DMARC builds on SPF and DKIM authentication mechanisms by ensuring that the sender's email domain aligns with the domain in the email's From header. This alignment helps verify the authenticity of the email sender. Policy Enforcement: Domain owners can set policies on how to handle unauthenticated emails. These policies can include monitoring only, quarantine (moving emails to spam), or rejecting unauthenticated emails outright. Reporting: DMARC provides domain owners with valuable feedback through aggregate and forensic reports. Aggregate reports show summary data on email authentication failures, while forensic reports provide detailed information on individual emails that fail DMARC checks, aiding in the identification and mitigation of potential phishing attempts. Visibility: By aggregating data from recipient email servers, DMARC offers domain owners insight into who is sending emails on behalf of their domain, enabling them to detect and take action against malicious activities. Improved Email Deliverability: Authenticating emails with DMARC can enhance overall email deliverability rates, as receiving servers are more likely to trust and accept emails from authenticated sources. Implementing DMARC is a critical step in securing email communications and protecting an organization's brand reputation. By combining DMARC with SPF and DKIM, domain owners can establish a robust defense against email-based threats, contributing to a safer and more trustworthy email ecosystem. stands for Domain-based Message Authentication, Reporting, and Conformance. Fully aware that that may not have made anything clearer, let me explain.

Domain Keys Identified Mail (or DKIM DomainKeys Identified Mail (DKIM) is an email authentication method that allows the recipient to verify that an email was indeed sent and authorized by the owner of that domain. This is achieved through the use of cryptographic signatures, which are added to the email headers. When the email is received, the recipient's mail server uses the domain's public key, which is published in the DNS, to verify the signature. This ensures that the email has not been altered or forged in transit. Key features and benefits of DKIM include: Email Integrity: DKIM helps verify that the email content has not been tampered with during transmission, ensuring that it arrives in the same state in which it was sent. Authentication: By confirming that the sender's domain aligns with the domain in the DKIM signature, recipients can reliably identify the source of the email. Reputation Management: Consistently sending DKIM-signed emails can enhance the domain's reputation with email service providers, reducing the likelihood of emails being flagged as spam. Interoperability: DKIM works in conjunction with other email authentication mechanisms, such as SPF and DMARC, providing an additional layer of security. Transparency: DKIM operates in the background and does not impact the user's experience, as the verification process is transparent to the end user. Implementing DKIM helps organizations protect their email infrastructure against phishing and spoofing attacks, ensuring better trust and deliverability of their email communications. It is a crucial component of a comprehensive email security strategy when combined with SPF and DMARC. ) is very straightforward. When it is set up for your domain, your domain “locks” a version of the email and stores it in a corner of the email itself. The receiving email server uses a public key that your server makes available on the Internet to unlock that box and check that the version of the email it received matches the version locked by your server. If it does, the email has not been changed or tampered with. If it does not, the server knows that the email wasn’t sent by your server or was compromised, which can lead to the email being blocked or quarantined.

Domain-based Message Authentication, Reporting, and Conformance (or DMARC Domain-based Message Authentication, Reporting & Conformance (DMARC) is an email authentication protocol designed to give domain owners the ability to protect their domain from unauthorized use, commonly known as email spoofing. By implementing DMARC, domain owners can specify that their emails are protected by both SPF (Sender Policy Framework) and DKIM (DomainKeys Identified Mail) protocols, significantly reducing the risk of email fraud and phishing attacks. Key components and benefits of DMARC include: Authentication: DMARC builds on SPF and DKIM authentication mechanisms by ensuring that the sender's email domain aligns with the domain in the email's From header. This alignment helps verify the authenticity of the email sender. Policy Enforcement: Domain owners can set policies on how to handle unauthenticated emails. These policies can include monitoring only, quarantine (moving emails to spam), or rejecting unauthenticated emails outright. Reporting: DMARC provides domain owners with valuable feedback through aggregate and forensic reports. Aggregate reports show summary data on email authentication failures, while forensic reports provide detailed information on individual emails that fail DMARC checks, aiding in the identification and mitigation of potential phishing attempts. Visibility: By aggregating data from recipient email servers, DMARC offers domain owners insight into who is sending emails on behalf of their domain, enabling them to detect and take action against malicious activities. Improved Email Deliverability: Authenticating emails with DMARC can enhance overall email deliverability rates, as receiving servers are more likely to trust and accept emails from authenticated sources. Implementing DMARC is a critical step in securing email communications and protecting an organization's brand reputation. By combining DMARC with SPF and DKIM, domain owners can establish a robust defense against email-based threats, contributing to a safer and more trustworthy email ecosystem. ) allows your domain to check whether an email passes DKIM DomainKeys Identified Mail (DKIM) is an email authentication method that allows the recipient to verify that an email was indeed sent and authorized by the owner of that domain. This is achieved through the use of cryptographic signatures, which are added to the email headers. When the email is received, the recipient's mail server uses the domain's public key, which is published in the DNS, to verify the signature. This ensures that the email has not been altered or forged in transit. Key features and benefits of DKIM include: Email Integrity: DKIM helps verify that the email content has not been tampered with during transmission, ensuring that it arrives in the same state in which it was sent. Authentication: By confirming that the sender's domain aligns with the domain in the DKIM signature, recipients can reliably identify the source of the email. Reputation Management: Consistently sending DKIM-signed emails can enhance the domain's reputation with email service providers, reducing the likelihood of emails being flagged as spam. Interoperability: DKIM works in conjunction with other email authentication mechanisms, such as SPF and DMARC, providing an additional layer of security. Transparency: DKIM operates in the background and does not impact the user's experience, as the verification process is transparent to the end user. Implementing DKIM helps organizations protect their email infrastructure against phishing and spoofing attacks, ensuring better trust and deliverability of their email communications. It is a crucial component of a comprehensive email security strategy when combined with SPF and DMARC. , check whether it passes SPF Sender Policy Framework (SPF) is an email authentication protocol designed to prevent spammers from sending messages on behalf of your domain. By using SPF, domain owners can specify which mail servers are authorized to send emails on their behalf. This is achieved by adding a special DNS record to the domain's DNS settings, listing the IP addresses of the authorized mail servers. When an email is received, the recipient's mail server performs an SPF check by comparing the sending server's IP address against the list of authorized IP addresses in the SPF record. If the IP address matches, the email is considered legitimate; if not, it may be marked as spam or rejected. Implementing SPF helps to enhance the security of email communications, reduce spam and phishing attacks, and improve the overall trustworthiness of an organization's email domain. (another method of email authentication), and combine the results into a single decision of whether to reject or quarantine non-compliant emails. It also sends all the information to a specific “reporting address” where you can consolidate reports to see exactly where and how email is failing for your domain. DMARC Domain-based Message Authentication, Reporting & Conformance (DMARC) is an email authentication protocol designed to give domain owners the ability to protect their domain from unauthorized use, commonly known as email spoofing. By implementing DMARC, domain owners can specify that their emails are protected by both SPF (Sender Policy Framework) and DKIM (DomainKeys Identified Mail) protocols, significantly reducing the risk of email fraud and phishing attacks. Key components and benefits of DMARC include: Authentication: DMARC builds on SPF and DKIM authentication mechanisms by ensuring that the sender's email domain aligns with the domain in the email's From header. This alignment helps verify the authenticity of the email sender. Policy Enforcement: Domain owners can set policies on how to handle unauthenticated emails. These policies can include monitoring only, quarantine (moving emails to spam), or rejecting unauthenticated emails outright. Reporting: DMARC provides domain owners with valuable feedback through aggregate and forensic reports. Aggregate reports show summary data on email authentication failures, while forensic reports provide detailed information on individual emails that fail DMARC checks, aiding in the identification and mitigation of potential phishing attempts. Visibility: By aggregating data from recipient email servers, DMARC offers domain owners insight into who is sending emails on behalf of their domain, enabling them to detect and take action against malicious activities. Improved Email Deliverability: Authenticating emails with DMARC can enhance overall email deliverability rates, as receiving servers are more likely to trust and accept emails from authenticated sources. Implementing DMARC is a critical step in securing email communications and protecting an organization's brand reputation. By combining DMARC with SPF and DKIM, domain owners can establish a robust defense against email-based threats, contributing to a safer and more trustworthy email ecosystem. is a powerful tool, not only for improving the deliverability of your emails but also for giving you visibility into how you can continue to make improvements.

The Nitty Gritty

To set up DKIM DomainKeys Identified Mail (DKIM) is an email authentication method that allows the recipient to verify that an email was indeed sent and authorized by the owner of that domain. This is achieved through the use of cryptographic signatures, which are added to the email headers. When the email is received, the recipient's mail server uses the domain's public key, which is published in the DNS, to verify the signature. This ensures that the email has not been altered or forged in transit. Key features and benefits of DKIM include: Email Integrity: DKIM helps verify that the email content has not been tampered with during transmission, ensuring that it arrives in the same state in which it was sent. Authentication: By confirming that the sender's domain aligns with the domain in the DKIM signature, recipients can reliably identify the source of the email. Reputation Management: Consistently sending DKIM-signed emails can enhance the domain's reputation with email service providers, reducing the likelihood of emails being flagged as spam. Interoperability: DKIM works in conjunction with other email authentication mechanisms, such as SPF and DMARC, providing an additional layer of security. Transparency: DKIM operates in the background and does not impact the user's experience, as the verification process is transparent to the end user. Implementing DKIM helps organizations protect their email infrastructure against phishing and spoofing attacks, ensuring better trust and deliverability of their email communications. It is a crucial component of a comprehensive email security strategy when combined with SPF and DMARC. for your domain, I won’t bore you with my attempt at a guide. The process is different depending on your email provider, but it almost always involves two parts:

1. Generating a key through your mail provider and
2. Publishing that key publicly using a DNS Domain Name Services (DNS) is a foundational component of the internet, often described as the "phonebook" of the web, that translates human-friendly domain names into IP addresses that computers use to identify each other on the network. This essential service allows users to access websites using familiar domain names (e.g., www.example.com) instead of having to remember complex numerical IP addresses. Key features and functions of DNS include: Domain Name Resolution: When a user enters a domain name in their web browser, DNS servers are queried to resolve the domain name to its corresponding IP address, enabling the browser to load the correct website. Distributed Database: The DNS system is a distributed database, meaning it is not stored in a single location but rather shared across a hierarchy of DNS servers worldwide, ensuring reliability and redundancy. Hierarchical Structure: DNS has a hierarchical structure with multiple levels, including top-level domains (TLDs), second-level domains, and subdomains, which help organize and manage domain names efficiently. DNS Records: Various types of DNS records are used to store information about domain names, such as A records (address records) that map domain names to IP addresses, MX records (mail exchange records) that direct email to the correct mail servers, and CNAME records (canonical name records) that alias one domain name to another. Caching: To improve performance and reduce the load on DNS servers, DNS responses are often cached temporarily by intermediate servers and clients, allowing subsequent requests to be resolved more quickly. Security Extensions (DNSSEC): DNSSEC adds an additional layer of security to DNS by enabling the verification of origin and integrity of the DNS data, protecting against certain types of attacks such as DNS spoofing and cache poisoning. Implementing and managing DNS correctly is crucial for ensuring reliable and secure internet access. Organizations often use DNS management tools and services to automate and streamline the process, ensuring that their domain names resolve correctly and efficiently. Proper DNS configuration enhances website performance, user experience, and overall internet security. record.

If you use Microsoft 365 for email, you can find a step-by-step guide here. If you use Google Workspace, the guide can be found here. If you have an on-premise exchange server, you may have to jump through a few extra hoops using a third-party plugin to sign outgoing mail. For other email providers, the specific methods differ, but the concepts are the same: one key to lock the emails, another published to your domain so that email servers can unlock them.

Setting up DMARC Domain-based Message Authentication, Reporting & Conformance (DMARC) is an email authentication protocol designed to give domain owners the ability to protect their domain from unauthorized use, commonly known as email spoofing. By implementing DMARC, domain owners can specify that their emails are protected by both SPF (Sender Policy Framework) and DKIM (DomainKeys Identified Mail) protocols, significantly reducing the risk of email fraud and phishing attacks. Key components and benefits of DMARC include: Authentication: DMARC builds on SPF and DKIM authentication mechanisms by ensuring that the sender's email domain aligns with the domain in the email's From header. This alignment helps verify the authenticity of the email sender. Policy Enforcement: Domain owners can set policies on how to handle unauthenticated emails. These policies can include monitoring only, quarantine (moving emails to spam), or rejecting unauthenticated emails outright. Reporting: DMARC provides domain owners with valuable feedback through aggregate and forensic reports. Aggregate reports show summary data on email authentication failures, while forensic reports provide detailed information on individual emails that fail DMARC checks, aiding in the identification and mitigation of potential phishing attempts. Visibility: By aggregating data from recipient email servers, DMARC offers domain owners insight into who is sending emails on behalf of their domain, enabling them to detect and take action against malicious activities. Improved Email Deliverability: Authenticating emails with DMARC can enhance overall email deliverability rates, as receiving servers are more likely to trust and accept emails from authenticated sources. Implementing DMARC is a critical step in securing email communications and protecting an organization's brand reputation. By combining DMARC with SPF and DKIM, domain owners can establish a robust defense against email-based threats, contributing to a safer and more trustworthy email ecosystem. requires a DNS Domain Name Services (DNS) is a foundational component of the internet, often described as the "phonebook" of the web, that translates human-friendly domain names into IP addresses that computers use to identify each other on the network. This essential service allows users to access websites using familiar domain names (e.g., www.example.com) instead of having to remember complex numerical IP addresses. Key features and functions of DNS include: Domain Name Resolution: When a user enters a domain name in their web browser, DNS servers are queried to resolve the domain name to its corresponding IP address, enabling the browser to load the correct website. Distributed Database: The DNS system is a distributed database, meaning it is not stored in a single location but rather shared across a hierarchy of DNS servers worldwide, ensuring reliability and redundancy. Hierarchical Structure: DNS has a hierarchical structure with multiple levels, including top-level domains (TLDs), second-level domains, and subdomains, which help organize and manage domain names efficiently. DNS Records: Various types of DNS records are used to store information about domain names, such as A records (address records) that map domain names to IP addresses, MX records (mail exchange records) that direct email to the correct mail servers, and CNAME records (canonical name records) that alias one domain name to another. Caching: To improve performance and reduce the load on DNS servers, DNS responses are often cached temporarily by intermediate servers and clients, allowing subsequent requests to be resolved more quickly. Security Extensions (DNSSEC): DNSSEC adds an additional layer of security to DNS by enabling the verification of origin and integrity of the DNS data, protecting against certain types of attacks such as DNS spoofing and cache poisoning. Implementing and managing DNS correctly is crucial for ensuring reliable and secure internet access. Organizations often use DNS management tools and services to automate and streamline the process, ensuring that their domain names resolve correctly and efficiently. Proper DNS configuration enhances website performance, user experience, and overall internet security. record containing your DMARC Domain-based Message Authentication, Reporting & Conformance (DMARC) is an email authentication protocol designed to give domain owners the ability to protect their domain from unauthorized use, commonly known as email spoofing. By implementing DMARC, domain owners can specify that their emails are protected by both SPF (Sender Policy Framework) and DKIM (DomainKeys Identified Mail) protocols, significantly reducing the risk of email fraud and phishing attacks. Key components and benefits of DMARC include: Authentication: DMARC builds on SPF and DKIM authentication mechanisms by ensuring that the sender's email domain aligns with the domain in the email's From header. This alignment helps verify the authenticity of the email sender. Policy Enforcement: Domain owners can set policies on how to handle unauthenticated emails. These policies can include monitoring only, quarantine (moving emails to spam), or rejecting unauthenticated emails outright. Reporting: DMARC provides domain owners with valuable feedback through aggregate and forensic reports. Aggregate reports show summary data on email authentication failures, while forensic reports provide detailed information on individual emails that fail DMARC checks, aiding in the identification and mitigation of potential phishing attempts. Visibility: By aggregating data from recipient email servers, DMARC offers domain owners insight into who is sending emails on behalf of their domain, enabling them to detect and take action against malicious activities. Improved Email Deliverability: Authenticating emails with DMARC can enhance overall email deliverability rates, as receiving servers are more likely to trust and accept emails from authenticated sources. Implementing DMARC is a critical step in securing email communications and protecting an organization's brand reputation. By combining DMARC with SPF and DKIM, domain owners can establish a robust defense against email-based threats, contributing to a safer and more trustworthy email ecosystem. policy (what you do with mail depending on how it passes SPF Sender Policy Framework (SPF) is an email authentication protocol designed to prevent spammers from sending messages on behalf of your domain. By using SPF, domain owners can specify which mail servers are authorized to send emails on their behalf. This is achieved by adding a special DNS record to the domain's DNS settings, listing the IP addresses of the authorized mail servers. When an email is received, the recipient's mail server performs an SPF check by comparing the sending server's IP address against the list of authorized IP addresses in the SPF record. If the IP address matches, the email is considered legitimate; if not, it may be marked as spam or rejected. Implementing SPF helps to enhance the security of email communications, reduce spam and phishing attacks, and improve the overall trustworthiness of an organization's email domain. and DKIM DomainKeys Identified Mail (DKIM) is an email authentication method that allows the recipient to verify that an email was indeed sent and authorized by the owner of that domain. This is achieved through the use of cryptographic signatures, which are added to the email headers. When the email is received, the recipient's mail server uses the domain's public key, which is published in the DNS, to verify the signature. This ensures that the email has not been altered or forged in transit. Key features and benefits of DKIM include: Email Integrity: DKIM helps verify that the email content has not been tampered with during transmission, ensuring that it arrives in the same state in which it was sent. Authentication: By confirming that the sender's domain aligns with the domain in the DKIM signature, recipients can reliably identify the source of the email. Reputation Management: Consistently sending DKIM-signed emails can enhance the domain's reputation with email service providers, reducing the likelihood of emails being flagged as spam. Interoperability: DKIM works in conjunction with other email authentication mechanisms, such as SPF and DMARC, providing an additional layer of security. Transparency: DKIM operates in the background and does not impact the user's experience, as the verification process is transparent to the end user. Implementing DKIM helps organizations protect their email infrastructure against phishing and spoofing attacks, ensuring better trust and deliverability of their email communications. It is a crucial component of a comprehensive email security strategy when combined with SPF and DMARC. ) published to your domain, with the prerequisite that you have SPF Sender Policy Framework (SPF) is an email authentication protocol designed to prevent spammers from sending messages on behalf of your domain. By using SPF, domain owners can specify which mail servers are authorized to send emails on their behalf. This is achieved by adding a special DNS record to the domain's DNS settings, listing the IP addresses of the authorized mail servers. When an email is received, the recipient's mail server performs an SPF check by comparing the sending server's IP address against the list of authorized IP addresses in the SPF record. If the IP address matches, the email is considered legitimate; if not, it may be marked as spam or rejected. Implementing SPF helps to enhance the security of email communications, reduce spam and phishing attacks, and improve the overall trustworthiness of an organization's email domain. and DKIM DomainKeys Identified Mail (DKIM) is an email authentication method that allows the recipient to verify that an email was indeed sent and authorized by the owner of that domain. This is achieved through the use of cryptographic signatures, which are added to the email headers. When the email is received, the recipient's mail server uses the domain's public key, which is published in the DNS, to verify the signature. This ensures that the email has not been altered or forged in transit. Key features and benefits of DKIM include: Email Integrity: DKIM helps verify that the email content has not been tampered with during transmission, ensuring that it arrives in the same state in which it was sent. Authentication: By confirming that the sender's domain aligns with the domain in the DKIM signature, recipients can reliably identify the source of the email. Reputation Management: Consistently sending DKIM-signed emails can enhance the domain's reputation with email service providers, reducing the likelihood of emails being flagged as spam. Interoperability: DKIM works in conjunction with other email authentication mechanisms, such as SPF and DMARC, providing an additional layer of security. Transparency: DKIM operates in the background and does not impact the user's experience, as the verification process is transparent to the end user. Implementing DKIM helps organizations protect their email infrastructure against phishing and spoofing attacks, ensuring better trust and deliverability of their email communications. It is a crucial component of a comprehensive email security strategy when combined with SPF and DMARC. both functional already. You may also benefit from using a service like EasyDMARC, which consolidates and clarifies the reports sent by your new DMARC Domain-based Message Authentication, Reporting & Conformance (DMARC) is an email authentication protocol designed to give domain owners the ability to protect their domain from unauthorized use, commonly known as email spoofing. By implementing DMARC, domain owners can specify that their emails are protected by both SPF (Sender Policy Framework) and DKIM (DomainKeys Identified Mail) protocols, significantly reducing the risk of email fraud and phishing attacks. Key components and benefits of DMARC include: Authentication: DMARC builds on SPF and DKIM authentication mechanisms by ensuring that the sender's email domain aligns with the domain in the email's From header. This alignment helps verify the authenticity of the email sender. Policy Enforcement: Domain owners can set policies on how to handle unauthenticated emails. These policies can include monitoring only, quarantine (moving emails to spam), or rejecting unauthenticated emails outright. Reporting: DMARC provides domain owners with valuable feedback through aggregate and forensic reports. Aggregate reports show summary data on email authentication failures, while forensic reports provide detailed information on individual emails that fail DMARC checks, aiding in the identification and mitigation of potential phishing attempts. Visibility: By aggregating data from recipient email servers, DMARC offers domain owners insight into who is sending emails on behalf of their domain, enabling them to detect and take action against malicious activities. Improved Email Deliverability: Authenticating emails with DMARC can enhance overall email deliverability rates, as receiving servers are more likely to trust and accept emails from authenticated sources. Implementing DMARC is a critical step in securing email communications and protecting an organization's brand reputation. By combining DMARC with SPF and DKIM, domain owners can establish a robust defense against email-based threats, contributing to a safer and more trustworthy email ecosystem. policy, making it much easier to take action on deliverability issues.

A Parting Thought

This may sound like more trouble than it’s worth, and ten years ago, I would have agreed with you. But times change quickly in IT, and the field is constantly being pushed forward by corporations like Microsoft and Google, which continue to set higher and higher standards for security. I was working recently with a client who couldn’t email more than one or two Gmail users at once. I thought this was odd because his email was hosted through 365, so Microsoft should be taking care of most of his issues.

However, as I researched the problem, I found that countless other individuals were reporting the same thing with no solution offered by Microsoft. I reluctantly instructed my client to put in a ticket with Microsoft. There was nothing more I could do. Then, a couple of days later, I noticed an alert from Microsoft on several of the tenants we manage, letting us know that since September 19, domains in Microsoft 365 may have issues sending to multiple recipients at once.

There was one exception, though. Microsoft stated (and I quote), “If your sending domain is configured with email authentication records like Sender Policy Framework ( SPF Sender Policy Framework (SPF) is an email authentication protocol designed to prevent spammers from sending messages on behalf of your domain. By using SPF, domain owners can specify which mail servers are authorized to send emails on their behalf. This is achieved by adding a special DNS record to the domain's DNS settings, listing the IP addresses of the authorized mail servers. When an email is received, the recipient's mail server performs an SPF check by comparing the sending server's IP address against the list of authorized IP addresses in the SPF record. If the IP address matches, the email is considered legitimate; if not, it may be marked as spam or rejected. Implementing SPF helps to enhance the security of email communications, reduce spam and phishing attacks, and improve the overall trustworthiness of an organization's email domain. ), DomainKeys Identified Mail ( DKIM DomainKeys Identified Mail (DKIM) is an email authentication method that allows the recipient to verify that an email was indeed sent and authorized by the owner of that domain. This is achieved through the use of cryptographic signatures, which are added to the email headers. When the email is received, the recipient's mail server uses the domain's public key, which is published in the DNS, to verify the signature. This ensures that the email has not been altered or forged in transit. Key features and benefits of DKIM include: Email Integrity: DKIM helps verify that the email content has not been tampered with during transmission, ensuring that it arrives in the same state in which it was sent. Authentication: By confirming that the sender's domain aligns with the domain in the DKIM signature, recipients can reliably identify the source of the email. Reputation Management: Consistently sending DKIM-signed emails can enhance the domain's reputation with email service providers, reducing the likelihood of emails being flagged as spam. Interoperability: DKIM works in conjunction with other email authentication mechanisms, such as SPF and DMARC, providing an additional layer of security. Transparency: DKIM operates in the background and does not impact the user's experience, as the verification process is transparent to the end user. Implementing DKIM helps organizations protect their email infrastructure against phishing and spoofing attacks, ensuring better trust and deliverability of their email communications. It is a crucial component of a comprehensive email security strategy when combined with SPF and DMARC. ), and Domain-based Message Authentication, Reporting, and Conformance ( DMARC Domain-based Message Authentication, Reporting & Conformance (DMARC) is an email authentication protocol designed to give domain owners the ability to protect their domain from unauthorized use, commonly known as email spoofing. By implementing DMARC, domain owners can specify that their emails are protected by both SPF (Sender Policy Framework) and DKIM (DomainKeys Identified Mail) protocols, significantly reducing the risk of email fraud and phishing attacks. Key components and benefits of DMARC include: Authentication: DMARC builds on SPF and DKIM authentication mechanisms by ensuring that the sender's email domain aligns with the domain in the email's From header. This alignment helps verify the authenticity of the email sender. Policy Enforcement: Domain owners can set policies on how to handle unauthenticated emails. These policies can include monitoring only, quarantine (moving emails to spam), or rejecting unauthenticated emails outright. Reporting: DMARC provides domain owners with valuable feedback through aggregate and forensic reports. Aggregate reports show summary data on email authentication failures, while forensic reports provide detailed information on individual emails that fail DMARC checks, aiding in the identification and mitigation of potential phishing attempts. Visibility: By aggregating data from recipient email servers, DMARC offers domain owners insight into who is sending emails on behalf of their domain, enabling them to detect and take action against malicious activities. Improved Email Deliverability: Authenticating emails with DMARC can enhance overall email deliverability rates, as receiving servers are more likely to trust and accept emails from authenticated sources. Implementing DMARC is a critical step in securing email communications and protecting an organization's brand reputation. By combining DMARC with SPF and DKIM, domain owners can establish a robust defense against email-based threats, contributing to a safer and more trustworthy email ecosystem. ) in Domain Name System ( DNS Domain Name Services (DNS) is a foundational component of the internet, often described as the "phonebook" of the web, that translates human-friendly domain names into IP addresses that computers use to identify each other on the network. This essential service allows users to access websites using familiar domain names (e.g., www.example.com) instead of having to remember complex numerical IP addresses. Key features and functions of DNS include: Domain Name Resolution: When a user enters a domain name in their web browser, DNS servers are queried to resolve the domain name to its corresponding IP address, enabling the browser to load the correct website. Distributed Database: The DNS system is a distributed database, meaning it is not stored in a single location but rather shared across a hierarchy of DNS servers worldwide, ensuring reliability and redundancy. Hierarchical Structure: DNS has a hierarchical structure with multiple levels, including top-level domains (TLDs), second-level domains, and subdomains, which help organize and manage domain names efficiently. DNS Records: Various types of DNS records are used to store information about domain names, such as A records (address records) that map domain names to IP addresses, MX records (mail exchange records) that direct email to the correct mail servers, and CNAME records (canonical name records) that alias one domain name to another. Caching: To improve performance and reduce the load on DNS servers, DNS responses are often cached temporarily by intermediate servers and clients, allowing subsequent requests to be resolved more quickly. Security Extensions (DNSSEC): DNSSEC adds an additional layer of security to DNS by enabling the verification of origin and integrity of the DNS data, protecting against certain types of attacks such as DNS spoofing and cache poisoning. Implementing and managing DNS correctly is crucial for ensuring reliable and secure internet access. Organizations often use DNS management tools and services to automate and streamline the process, ensuring that their domain names resolve correctly and efficiently. Proper DNS configuration enhances website performance, user experience, and overall internet security. )… you’re not impacted and your organization requires no action.”

You never know what new glitch might lie around the corner in the world of electronic mail, but configuring DMARC Domain-based Message Authentication, Reporting & Conformance (DMARC) is an email authentication protocol designed to give domain owners the ability to protect their domain from unauthorized use, commonly known as email spoofing. By implementing DMARC, domain owners can specify that their emails are protected by both SPF (Sender Policy Framework) and DKIM (DomainKeys Identified Mail) protocols, significantly reducing the risk of email fraud and phishing attacks. Key components and benefits of DMARC include: Authentication: DMARC builds on SPF and DKIM authentication mechanisms by ensuring that the sender's email domain aligns with the domain in the email's From header. This alignment helps verify the authenticity of the email sender. Policy Enforcement: Domain owners can set policies on how to handle unauthenticated emails. These policies can include monitoring only, quarantine (moving emails to spam), or rejecting unauthenticated emails outright. Reporting: DMARC provides domain owners with valuable feedback through aggregate and forensic reports. Aggregate reports show summary data on email authentication failures, while forensic reports provide detailed information on individual emails that fail DMARC checks, aiding in the identification and mitigation of potential phishing attempts. Visibility: By aggregating data from recipient email servers, DMARC offers domain owners insight into who is sending emails on behalf of their domain, enabling them to detect and take action against malicious activities. Improved Email Deliverability: Authenticating emails with DMARC can enhance overall email deliverability rates, as receiving servers are more likely to trust and accept emails from authenticated sources. Implementing DMARC is a critical step in securing email communications and protecting an organization's brand reputation. By combining DMARC with SPF and DKIM, domain owners can establish a robust defense against email-based threats, contributing to a safer and more trustworthy email ecosystem. and DKIM DomainKeys Identified Mail (DKIM) is an email authentication method that allows the recipient to verify that an email was indeed sent and authorized by the owner of that domain. This is achieved through the use of cryptographic signatures, which are added to the email headers. When the email is received, the recipient's mail server uses the domain's public key, which is published in the DNS, to verify the signature. This ensures that the email has not been altered or forged in transit. Key features and benefits of DKIM include: Email Integrity: DKIM helps verify that the email content has not been tampered with during transmission, ensuring that it arrives in the same state in which it was sent. Authentication: By confirming that the sender's domain aligns with the domain in the DKIM signature, recipients can reliably identify the source of the email. Reputation Management: Consistently sending DKIM-signed emails can enhance the domain's reputation with email service providers, reducing the likelihood of emails being flagged as spam. Interoperability: DKIM works in conjunction with other email authentication mechanisms, such as SPF and DMARC, providing an additional layer of security. Transparency: DKIM operates in the background and does not impact the user's experience, as the verification process is transparent to the end user. Implementing DKIM helps organizations protect their email infrastructure against phishing and spoofing attacks, ensuring better trust and deliverability of their email communications. It is a crucial component of a comprehensive email security strategy when combined with SPF and DMARC. for your domain will go a long way toward making sure that your emails stay high, dry, and untouched by the grubby fingers of spam filters or the rejection notices of adamantine Gmail servers.