Do government agencies block HTML emails?

Summary

Government agencies often implement stringent security measures to protect their networks from email-based threats, which frequently includes blocking or stripping HTML content from emails. This practice is due to concerns about phishing attacks, malware distribution, and other security vulnerabilities associated with HTML emails. While there is no universal policy, the approach varies by agency, department, and even specific office. Authentication protocols like SPF, DKIM, and DMARC are crucial for improving deliverability. Offering a plain text version of emails or securing explicit approval from the agency's IT department can also help ensure successful delivery.

Key findings

  • HTML Blocking: Government agencies commonly block or strip HTML from emails as a security precaution.
  • Varied Policies: Email policies and practices vary widely across different government entities.
  • Security Focus: The primary driver for blocking HTML is to mitigate security risks like phishing and malware.
  • Authentication Importance: Proper email authentication (SPF, DKIM, DMARC) significantly improves deliverability rates.
  • .mil Specificity: '.mil' domains and similar secure networks often have particularly stringent security protocols.

Key considerations

  • Email Authentication: Ensure robust email authentication using SPF, DKIM, and DMARC.
  • Plain Text Option: Offer a plain text version of your emails to ensure delivery even if HTML is blocked.
  • Sender Reputation: Maintain a good sender reputation to minimize the chances of being flagged as spam.
  • Content Optimization: Optimize email content to avoid triggering spam filters and security systems.
  • Agency Approval: If possible, seek approval from the government agency's IT department before sending HTML emails.

What email marketers say
11Marketer opinions

Government agencies often employ stricter security measures that may include blocking HTML emails, stripping out images, or disabling links. There is no blanket policy, and practices can vary widely by agency, department, and even specific user settings. Agencies often scrutinize HTML content to block potential threats, impacting marketing campaigns. Obtaining explicit approval from the agency may be required to send HTML emails successfully. Adhering to email deliverability best practices, authenticating emails (SPF, DKIM, DMARC), and maintaining a clean sending reputation are crucial for ensuring deliverability to government domains.

Key opinions

  • HTML Blocking: Government agencies commonly block or strip HTML from emails as a security precaution against phishing attacks and malware.
  • Varied Policies: Email policies vary significantly across different government agencies, departments, and even individual offices.
  • Approval Required: Some government entities require explicit approval before allowing HTML emails to be delivered, especially those containing links.
  • Stringent Security: Government agencies implement stringent email security protocols to protect their networks from potential threats.
  • Deliverability Challenges: Deliverability to government domains can be challenging due to strict spam filters, image blocking, and link validation processes.

Key considerations

  • Authentication: Ensure robust email authentication protocols (SPF, DKIM, DMARC) are in place to improve deliverability.
  • Sender Reputation: Maintain a clean sending reputation and avoid spam triggers to increase the likelihood of emails reaching government inboxes.
  • Content Optimization: Optimize email content to minimize the risk of being flagged as spam. Consider using plain text emails or offering a plain text version alongside HTML.
  • Engagement Practices: Monitor and optimize engagement practices to maintain a positive sender reputation and avoid being marked as spam.
  • Compliance: Adhere to all relevant email marketing regulations and best practices when sending to government agencies.
Marketer view

Email marketer from Campaign Monitor advises that adhering to email deliverability best practices is essential when sending to government agencies. Focus on authenticating your emails, maintaining a clean sending reputation, and avoiding spam triggers. Government entities often have stricter spam filters that can flag HTML emails containing certain content or formatting.

March 2023 - Campaign Monitor
Marketer view

Email marketer from Email Geeks explains that when emailing government entities, approval is needed to send HTML emails. If there is a contractual obligation and IT provides approval you can deliver an HTML email, with whatever links. It could take months to get approval and sometimes they will just say sorry, you can't email us.

March 2025 - Email Geeks
Marketer view

Email marketer from Mailjet Help Center explains that while there's no blanket policy, government agencies often employ stricter security measures. This may include blocking HTML emails, stripping out images, or disabling links to prevent potential security threats. This can vary widely by agency, department, and even specific user settings.

September 2024 - Mailjet Help Center
Marketer view

Email marketer from StackExchange responds that delivering to government entities necessitates adherence to stringent security standards. Agencies might block HTML to mitigate risks, especially if your email practices aren't fully compliant with security benchmarks, ensure robust authentication protocols (SPF, DKIM, DMARC) are in place to minimize deliverability hurdles.

July 2021 - StackExchange
Marketer view

Email marketer from Email Marketing Forum responds that delivering marketing emails to government sectors requires a detailed strategy that respects their security posture. Agencies often scrutinize HTML content to block potential threats, impacting marketing campaigns. It is essential to optimize email authentication and engagement practices to improve deliverability.

November 2024 - Email Marketing Forum
Marketer view

Email marketer from SocketLabs explains that government entities implement stringent security policies to protect their networks. A common strategy involves blocking HTML emails, particularly those from external sources. HTML emails are seen as a potential vector for phishing attacks and malware distribution, making them subject to strict filtering.

December 2023 - SocketLabs
Marketer view

Email marketer from Reddit explains that many government agencies use advanced email filtering systems. These systems are often configured to block HTML emails as a precaution against phishing attacks and malware. The user also notes that even if HTML emails are not blocked outright, images and links are frequently disabled.

August 2022 - Reddit
Marketer view

Email marketer from Gmass shares that delivering to government domains can be tough for several reasons. Strict security measures, spam filters, and authentication requirements are some of the reasons why emails may not reach their intended recipients. This often includes blocking HTML emails, especially if they are perceived as a security threat.

January 2023 - Gmass
Marketer view

Email marketer from EmailToolTester Blog shares that deliverability to government domains can be challenging. Government agencies often have stringent email security protocols, which may result in HTML emails being blocked or significantly altered. Factors contributing to this include strict spam filters, image blocking, and link validation processes.

November 2022 - EmailToolTester Blog
Marketer view

Marketer from Email Geeks recounts experience with a media brand's newsletters targeting government/military, frequently seeing stripping or blocking of HTML emails. Mentions variations even within the same office/department, with .mil typically stripping or blocking.

July 2022 - Email Geeks
Marketer view

Marketer from Email Geeks shares that they have encountered instances where US government agencies block HTML emails, varying by agency and even office. Mentions .mil as an example.

May 2022 - Email Geeks

What the experts say
3Expert opinions

Government agencies, especially those with secure networks like '.mil', often implement stringent security measures that include blocking or stripping HTML from emails to mitigate security threats such as malicious scripts and content. Employing email authentication (SPF, DKIM, DMARC) is crucial for ensuring deliverability, and in some cases, using plain text emails or providing a plain text alternative is recommended to bypass sophisticated filtering systems.

Key opinions

  • HTML Blocking: Government agencies block or strip HTML emails as a security measure.
  • Security Threats: This is done to prevent malicious scripts and content from reaching employees.
  • .mil Specificity: .mil domains and similar secure networks have heightened security protocols.
  • Sophisticated Filtering: Government entities utilize advanced email filtering systems that may flag HTML emails as potential threats.

Key considerations

  • Email Authentication: Ensure SPF, DKIM, and DMARC are correctly configured to enhance deliverability.
  • Plain Text Alternative: Consider providing a plain text version of your emails to ensure messages get through filtering systems.
  • Sender Reputation: Maintain a good sender reputation to improve email delivery rates.
Expert view

Expert from Spamresource.com responds that because government agencies are vigilant about security threats, agencies will often strip HTML from emails. This is often to prevent malicious scripts and content from reaching their employees. Ensuring email authentication (SPF, DKIM, DMARC) is configured correctly helps ensure deliverability.

August 2022 - Spamresource.com
Expert view

Expert from Wordtothewise.com explains that government entities often have sophisticated email filtering systems that may flag HTML emails as potential threats. It is recommended to use plain text emails for important communications or offer a plain text version alongside the HTML version to ensure messages get through. Authentication and a good sender reputation will help as well.

March 2023 - Wordtothewise.com
Expert view

Expert from Email Geeks mentions that '.mil' is a unique case and other secure networks may have similar measures regarding blocking HTML emails.

May 2023 - Email Geeks

What the documentation says
4Technical articles

Security documentation from NIST, US-CERT, and SANS Institute highlights the importance of mitigating risks associated with HTML content in emails, often recommending blocking HTML emails as a best practice. Government agencies implement strict filtering policies and security measures to reduce the risk of malware, phishing attacks, and other email-based threats. While DKIM improves overall email security and authentication, HTML blocking is a direct preventative measure.

Key findings

  • Risk Mitigation: HTML content in emails presents significant security risks.
  • Blocking Recommendation: Disabling or blocking HTML emails is recommended as a key security practice.
  • Security Measures: Government agencies implement strict filtering policies and security measures against email-based threats.
  • DKIM Authentication: DKIM improves email security but does not directly address HTML blocking.

Key considerations

  • Security Strategy: Incorporate HTML blocking into overall cybersecurity strategy.
  • Advanced Detection: Implement advanced threat detection systems to identify and mitigate email-based threats.
  • Email Client Configuration: Configure email clients and servers to prevent HTML rendering, reducing potential attack vectors.
  • Compliance: Refer to NIST SP 800-45 Version 2 and other guidelines for specific implementation details
Technical article

Documentation from DKIM explains DKIM's role in email authentication and security. Government agencies increasingly rely on DKIM to verify the authenticity of incoming emails. While DKIM doesn't directly address HTML blocking, it improves overall email security and reduces the likelihood of legitimate emails being flagged as spam or malicious.

October 2022 - DKIM.org
Technical article

Documentation from US-CERT shares strategies for mitigating email-based threats, including those associated with HTML emails. Government agencies are advised to implement security measures such as blocking HTML content, disabling links, and employing advanced threat detection systems. Provides insight into common email attack vectors and preventative measures.

January 2024 - United States Computer Emergency Readiness Team
Technical article

Documentation from NIST outlines security guidelines for email, highlighting the importance of mitigating risks associated with HTML content. Agencies may choose to block HTML emails or implement strict filtering policies as part of their overall cybersecurity strategy. Refer to SP 800-45 Version 2 for guidance.

June 2022 - National Institute of Standards and Technology
Technical article

Documentation from SANS Institute recommends disabling HTML emails as a security best practice. Government agencies and other organizations should consider blocking HTML content to reduce the risk of malware and phishing attacks. Includes guidelines for configuring email clients and servers to prevent HTML rendering.

May 2021 - SANS Institute