Preventing email spoofing – SPF, DKIM and DMARC in detail

Mail spoofingEmail spoofing is a technique of forging an email header into tricking recipients into thinking the sender is a well-known brand or friend. Source & further information Spoofing is a common technique used by attackers. These fake (“spoofing”) messages appear to be from a source other than the actual source . This method is often used in phishing campaigns that... is a serious threat in the digital world, affecting both large organizations and individuals. When attackers are able to spoof the sender address in emails, they open the door to a variety of fraudulent activities, including phishing Phishing is an attempt to steal other people's personal data (such as passwords, credit card numbers, etc.) using fake e-mails or websites.
EOP can help you block these emails with extended phishing thresholds. and malware distribution. Robust authentication and validation mechanisms are required to ward off such attacks and ensure the integrity of e-mail communication. This is where technologies such as SPF (Sender Policy Framework), DKIM DKIM (Domain Keys Identified Mail) is a method of e-mail authentication that uses a signature to make it difficult for the sender to falsify. Many providers of e-mail gateways are currently already using two DKIM keys to achieve even more security. Source & further information 2nd source (DomainKeys Identified Mail) and DMARCA DMARC record is one of the lines in your website's DNS records. It was developed to make it more difficult for spammers to "spoof" your domain, which means that they pretend to use your domain as the real sender. DMARC really helps ensure that phishing emails and malware cannot be sent from your email address.
(Domain-based Message Authentication, Reporting, and Conformance) come into play. These technologies are crucial for preventing mail spoofingEmail spoofing is a technique of forging an email header into tricking recipients into thinking the sender is a well-known brand or friend. Source & further information Spoofing is a common technique used by attackers. These fake (“spoofing”) messages appear to be from a source other than the actual source . This method is often used in phishing campaigns that... and creating a secure email environment. There are also other measures and best practices that can help improve email security, especially in environments such as Exchange Microsoft Exchange is more than just an e-mail solution, because it offers a diverse range of tools to better structure and organize your daily work. In addition, with its team functions, it makes collaboration and communication in the team much easier. On top of that, there is also the fact that it can be used with the other cloud services... Online and M365 Defender.

Tools such as“mxtoolbox.com” can be a great help in analyzing the current configurations.

SPF (Sender Policy Framework):

Identifying the mail servers: First you need to identify all mail servers that are authorized to send emails for your domainA domain is a name that is unique and unambiguous worldwide on the Internet. The domain can be used for websites and emails.. This includes your primary and secondary mail servers as well as any third-party services you may use.

Creating the SPF recordSPF is the abbreviation for "Sender Policy Framework". With this method, mail servers can check whether the mail they receive actually originates from the declared host server. This SPF check is carried out fully automatically in the background; as the end user, you will not notice any of this. In simple terms, the SPF specifies which mail servers are allowed...: Create a TXT record in your DNSDomain Name System (DNS) is a decentralized search service that translates a human-readable domain name or URL into the IP address of the server hosting the website or service. This characteristic of the worldwide distribution of DNS is an important component of the Internet. DNS has been used since 1985. A DNS server serves two purposes. The first is to... zone. The data record always begins with the version (v=spf1), followed by the IP• Internet protocol: IP is responsible for addressing a data packet. IP encapsulates the data packet that is to be transmitted and adds an address header. The header contains information about the IP addresses of the sender and recipient. The order in which the packets are sent or received is irrelevant to the protocol. It also does not guarantee that... addresses of the authorized mail servers and a concluding policy.

Example:

SPF Qualifiers: You can use qualifiers to specify how recipients should handle mismatched emails:

• + Passport (accepts the e-mail)
• - Fail (rejects the e-mail)
• ~ SoftFail (accepts the e-mail, but marks it)
• ? Neutral (no action)

SPF mechanisms: Use different mechanisms to specify your mail servers:

• ip4: or ip6: for IP• Internet protocol: IP is responsible for addressing a data packet. IP encapsulates the data packet that is to be transmitted and adds an address header. The header contains information about the IP addresses of the sender and recipient. The order in which the packets are sent or received is irrelevant to the protocol. It also does not guarantee that... addresses
• a: for DNSDomain Name System (DNS) is a decentralized search service that translates a human-readable domain name or URL into the IP address of the server hosting the website or service. This characteristic of the worldwide distribution of DNS is an important component of the Internet. DNS has been used since 1985. A DNS server serves two purposes. The first is to... names
• mx: for Mail Exchanger
• include: for other domains’ SPF records

Testing the SPF dataset: After publishing your SPF recordSPF is the abbreviation for "Sender Policy Framework". With this method, mail servers can check whether the mail they receive actually originates from the declared host server. This SPF check is carried out fully automatically in the background; as the end user, you will not notice any of this. In simple terms, the SPF specifies which mail servers are allowed..., you should check that it works correctly by using SPF validation tools online.

DKIM (DomainKeys Identified Mail):

Create a key pair: Create a public-private key pair with a DKIM DKIM (Domain Keys Identified Mail) is a method of e-mail authentication that uses a signature to make it difficult for the sender to falsify. Many providers of e-mail gateways are currently already using two DKIM keys to achieve even more security. Source & further information 2nd source key generator.

Publish the public key: The public key is published in a TXT record in your DNSDomain Name System (DNS) is a decentralized search service that translates a human-readable domain name or URL into the IP address of the server hosting the website or service. This characteristic of the worldwide distribution of DNS is an important component of the Internet. DNS has been used since 1985. A DNS server serves two purposes. The first is to... zone. The data set is combined with a selector that identifies the key and your domainA domain is a name that is unique and unambiguous worldwide on the Internet. The domain can be used for websites and emails..

Example:

Configure the mail server: Configure your mail server so that it signs outgoing emails with the private key.

Testing the DKIM DKIM (Domain Keys Identified Mail) is a method of e-mail authentication that uses a signature to make it difficult for the sender to falsify. Many providers of e-mail gateways are currently already using two DKIM keys to achieve even more security. Source & further information 2nd source configuration: Send test emails and use DKIM DKIM (Domain Keys Identified Mail) is a method of e-mail authentication that uses a signature to make it difficult for the sender to falsify. Many providers of e-mail gateways are currently already using two DKIM keys to achieve even more security. Source & further information 2nd source validation tools to ensure that your emails are signed correctly.

DMARC (Domain-based Message Authentication, Reporting, and Conformance):

Creating the DMARCA DMARC record is one of the lines in your website's DNS records. It was developed to make it more difficult for spammers to "spoof" your domain, which means that they pretend to use your domain as the real sender. DMARC really helps ensure that phishing emails and malware cannot be sent from your email address.
record: The DMARCA DMARC record is one of the lines in your website's DNS records. It was developed to make it more difficult for spammers to "spoof" your domain, which means that they pretend to use your domain as the real sender. DMARC really helps ensure that phishing emails and malware cannot be sent from your email address.
record is created as a TXT record in your DNSDomain Name System (DNS) is a decentralized search service that translates a human-readable domain name or URL into the IP address of the server hosting the website or service. This characteristic of the worldwide distribution of DNS is an important component of the Internet. DNS has been used since 1985. A DNS server serves two purposes. The first is to... zone. The DMARCA DMARC record is one of the lines in your website's DNS records. It was developed to make it more difficult for spammers to "spoof" your domain, which means that they pretend to use your domain as the real sender. DMARC really helps ensure that phishing emails and malware cannot be sent from your email address.
policy defines how recipients should handle unauthenticated emails.

Example:

Select a DMARCA DMARC record is one of the lines in your website's DNS records. It was developed to make it more difficult for spammers to "spoof" your domain, which means that they pretend to use your domain as the real sender. DMARC really helps ensure that phishing emails and malware cannot be sent from your email address.
policy:

• p=none for no special treatment
• p=quarantine to mark e-mails as spam
• p=reject to reject unauthenticated e-mails

Set reporting options: You can set reporting options to receive feedback on DMARCA DMARC record is one of the lines in your website's DNS records. It was developed to make it more difficult for spammers to "spoof" your domain, which means that they pretend to use your domain as the real sender. DMARC really helps ensure that phishing emails and malware cannot be sent from your email address.
reviews.

Testing the DMARCA DMARC record is one of the lines in your website's DNS records. It was developed to make it more difficult for spammers to "spoof" your domain, which means that they pretend to use your domain as the real sender. DMARC really helps ensure that phishing emails and malware cannot be sent from your email address.
configuration: Send test emails and check the DMARCA DMARC record is one of the lines in your website's DNS records. It was developed to make it more difficult for spammers to "spoof" your domain, which means that they pretend to use your domain as the real sender. DMARC really helps ensure that phishing emails and malware cannot be sent from your email address.
reports to make sure your configuration is correct.

Further measures to prevent mail spoofing:

In addition to SPF, DKIM DKIM (Domain Keys Identified Mail) is a method of e-mail authentication that uses a signature to make it difficult for the sender to falsify. Many providers of e-mail gateways are currently already using two DKIM keys to achieve even more security. Source & further information 2nd source and DMARCA DMARC record is one of the lines in your website's DNS records. It was developed to make it more difficult for spammers to "spoof" your domain, which means that they pretend to use your domain as the real sender. DMARC really helps ensure that phishing emails and malware cannot be sent from your email address.
, there are other measures you can take to prevent mail spoofingEmail spoofing is a technique of forging an email header into tricking recipients into thinking the sender is a well-known brand or friend. Source & further information Spoofing is a common technique used by attackers. These fake (“spoofing”) messages appear to be from a source other than the actual source . This method is often used in phishing campaigns that...:

• Authenticated SMTPSimple Mail Transfer Protocol (SMTP): SMTP is another of the three email protocols. It is most commonly used for sending email from an email client through an email server. This protocol uses TCP for the administration and delivery of the e-mail. relays: Use authenticated SMTPSimple Mail Transfer Protocol (SMTP): SMTP is another of the three email protocols. It is most commonly used for sending email from an email client through an email server. This protocol uses TCP for the administration and delivery of the e-mail. relays to ensure that only authorized users and systems can send emails.
• Regularly check mail server configurations: Review your mail server configurations regularly to ensure they are up to date with the latest security best practices.
• End user training: Train users in your network on the dangers of phishing Phishing is an attempt to steal other people's personal data (such as passwords, credit card numbers, etc.) using fake e-mails or websites.
  EOP can help you block these emails with extended phishing thresholds. and how to recognize suspicious emails.

Best practices for Exchange Online and M365 Defender:

Configuration and best practices:

1. 1. Configure anti-phishing policy in Microsoft 365 Defender:
      • Define an anti-phishing policy that is specifically tailored to your organization to protect you from phishing Phishing is an attempt to steal other people's personal data (such as passwords, credit card numbers, etc.) using fake e-mails or websites.
        EOP can help you block these emails with extended phishing thresholds. attacks and mail spoofingEmail spoofing is a technique of forging an email header into tricking recipients into thinking the sender is a well-known brand or friend. Source & further information Spoofing is a common technique used by attackers. These fake (“spoofing”) messages appear to be from a source other than the actual source . This method is often used in phishing campaigns that.... Go to Microsoft 365-Sicherheitszentrum > Richtlinien & Regeln > Threat Policies > Anti-Phishing.
      • You can also add custom domains to be protected and configure the actions to be taken when phishing Phishing is an attempt to steal other people's personal data (such as passwords, credit card numbers, etc.) using fake e-mails or websites.
        EOP can help you block these emails with extended phishing thresholds. attempts are detected.
        1. Security guidelines for e-mail flow in Exchange Microsoft Exchange is more than just an e-mail solution, because it offers a diverse range of tools to better structure and organize your daily work. In addition, with its team functions, it makes collaboration and communication in the team much easier. On top of that, there is also the fact that it can be used with the other cloud services... Online:
           • Create mail flow rules (also known as transport rules) to control the delivery of emails and detect and block potential spoofingEmail spoofing is a technique of forging an email header into tricking recipients into thinking the sender is a well-known brand or friend. Source & further information Spoofing is a common technique used by attackers. These fake (“spoofing”) messages appear to be from a source other than the actual source . This method is often used in phishing campaigns that... attempts. Go to Exchange Admin Center > Mail Flow > Rules.
           • These rules can be based on various criteria, including sender domainA domain is a name that is unique and unambiguous worldwide on the Internet. The domain can be used for websites and emails., IP address• Internet protocol: IP is responsible for addressing a data packet. IP encapsulates the data packet that is to be transmitted and adds an address header. The header contains information about the IP addresses of the sender and recipient. The order in which the packets are sent or received is irrelevant to the protocol. It also does not guarantee that... and specific content within the email.
        2. Activate Microsoft Threat Protection:
           • Enable Microsoft Threat Protection to get a comprehensive view of threats across email, identityThis is something that needs to be identified and authenticated. An identity is typically a user who has login information in the form of a username and password. However, they can also be applications and services. and other vectors. Go to Microsoft 365 Sicherheitszentrum > Microsoft 365 Defender.
        3. Improvement of user information:
           • Provide training materials and conduct regular phishing Phishing is an attempt to steal other people's personal data (such as passwords, credit card numbers, etc.) using fake e-mails or websites.
             EOP can help you block these emails with extended phishing thresholds. simulations to improve awareness and detection of phishing Phishing is an attempt to steal other people's personal data (such as passwords, credit card numbers, etc.) using fake e-mails or websites.
             EOP can help you block these emails with extended phishing thresholds. and spoofingEmail spoofing is a technique of forging an email header into tricking recipients into thinking the sender is a well-known brand or friend. Source & further information Spoofing is a common technique used by attackers. These fake (“spoofing”) messages appear to be from a source other than the actual source . This method is often used in phishing campaigns that... attempts. You can do this via Microsoft 365 Sicherheitszentrum > Angriffssimulator.
        4. Automated examinations and reactions:
           • Use the automated investigation and response capabilities in Microsoft 365 to respond to and remediate suspicious activity, reducing the time between threat detection and remediation. Go to Microsoft 365 Sicherheitszentrum > Automatisierte Untersuchung & Reaktion.
        5. Configure Office 365 Advanced Threat Protection (ATP):
           • Configure Office 365 ATP safe attachment and safe link policies to provide additional protection against malicious attachments and links. You can find these options at Microsoft 365 Sicherheitszentrum > Richtlinien & Regeln > Threat Policies > ATP Safe Attachments and ATP Safe Links.
        6. Reporting and analysis:
           • Use the reporting tools and dashboard in Exchange Microsoft Exchange is more than just an e-mail solution, because it offers a diverse range of tools to better structure and organize your daily work. In addition, with its team functions, it makes collaboration and communication in the team much easier. On top of that, there is also the fact that it can be used with the other cloud services... Online and Microsoft 365 Defender to gain insights into email flow, phishing Phishing is an attempt to steal other people's personal data (such as passwords, credit card numbers, etc.) using fake e-mails or websites.
             EOP can help you block these emails with extended phishing thresholds. attempts and the effectiveness of your security measures. Go to Microsoft 365 Sicherheitszentrum > Berichte.
        7. Analyze external e-mail header:
           • Explain to your users how they can analyze email headers to verify the original source of an email and encourage the use of the suspicious message reporting tool in Outlook Microsoft Outlook is software with which emails can be sent and received and appointments, notes, contacts and tasks can be managed. Official Microsoft Outlook website.

        Consistently applying and reviewing these best practices and using the built-in security features of Exchange Microsoft Exchange is more than just an e-mail solution, because it offers a diverse range of tools to better structure and organize your daily work. In addition, with its team functions, it makes collaboration and communication in the team much easier. On top of that, there is also the fact that it can be used with the other cloud services... Online and Microsoft 365 Defender can go a long way toward minimizing the risk of mail spoofingEmail spoofing is a technique of forging an email header into tricking recipients into thinking the sender is a well-known brand or friend. Source & further information Spoofing is a common technique used by attackers. These fake (“spoofing”) messages appear to be from a source other than the actual source . This method is often used in phishing campaigns that... and improving overall email security.

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