How to resolve deliverability issues with .mil email addresses?

Summary

Resolving deliverability issues with .mil email addresses is complex due to their unique government-controlled nature and stricter security policies. Blocks are often unrelated to spam and result from DoD-specific rules. Key strategies include ensuring proper email authentication (SPF, DKIM, DMARC), monitoring sender reputation, and providing a plain text version. Segmenting lists, offering non-.mil addresses, and testing deliverability are also important. Furthermore, understanding and respecting content restrictions, getting explicit permission, and actively monitoring reputation are crucial for successful delivery.

Key findings

  • Government Control: .mil domains are government-controlled with unique rules differing from commercial ISPs.
  • Authentication: Proper authentication (SPF, DKIM, DMARC) is critical due to stricter policies.
  • Reputation Sensitivity: .mil domains are highly sensitive to sender reputation; monitor it closely.
  • Plain Text Requirement: Providing a plain text version is often necessary for older systems.
  • Content Restrictions: Non-official content is problematic; adhere to content guidelines.
  • Segmentation & Testing: Segment .mil addresses and perform specific deliverability testing.
  • Blocks Unrelated to Spam: Deliverability issues are frequently unrelated to traditional spam issues.

Key considerations

  • Sender Reputation: Proactively monitor and manage your sender reputation.
  • Recipient Permission: Obtain explicit permission from recipients to send emails.
  • Alternative Addresses: Offer recipients the option to use a non-.mil address for subscriptions.
  • Authentication Implementation: Implement and maintain proper SPF, DKIM, and DMARC records.
  • Content Alignment: Ensure email content aligns with official use guidelines.
  • Understanding .mil Policies: Familiarize yourself with the unique policies of .mil domains.
  • Feedback Loops: Implement feedback loops.

What email marketers say
9Marketer opinions

Resolving deliverability issues with .mil email addresses requires a multi-faceted approach due to their strict security policies and government-controlled nature. Key strategies include ensuring proper email authentication (SPF, DKIM, DMARC), monitoring sender reputation, providing a plain text version of emails, segmenting .mil addresses for targeted testing, and offering recipients the option to use non-.mil addresses. Additionally, it's crucial to avoid blacklists, comply with CAN-SPAM regulations, and test email deliverability using specialized tools to identify domain-specific issues. Understanding and adapting to the unique requirements of .mil domains is essential for successful email delivery.

Key opinions

  • Authentication: Proper authentication (SPF, DKIM, DMARC) is critical for .mil delivery.
  • Reputation: .mil domains are highly sensitive to sender reputation.
  • Content: Ensure compliance with CAN-SPAM and avoid triggering spam filters.
  • Segmentation: Segment .mil addresses for targeted testing and monitoring.
  • Plain Text: Include a plain text version for compatibility with older systems.
  • Alternative Addresses: Offer recipients the option to use non-.mil addresses.
  • Testing: Use deliverability tools to simulate .mil specific filters and identify issues.

Key considerations

  • Security Policies: Military domains have stricter security policies than commercial ISPs.
  • Blacklists: Regularly check if your sending IP is on any blacklists.
  • Monitoring: Continuously monitor sender reputation and deliverability metrics.
  • Compliance: Stay compliant with CAN-SPAM regulations and email best practices.
  • Technical Differences: Understand the technical differences and requirements of .mil systems.
Marketer view

Email marketer from SparkPost advises monitoring your sending reputation closely, as .mil domains are sensitive to IP reputation. Also, ensure your content doesn't trigger spam filters and that you are compliant with CAN-SPAM regulations.

September 2023 - SparkPost
Marketer view

Email marketer from StackExchange recommends performing a deliverability test using tools that simulate various email clients and spam filters to identify potential issues specific to .mil domains.

March 2024 - StackExchange
Marketer view

Email marketer from SendGrid advocates using reputation monitoring tools to track your sender score and identify any issues that may affect email deliverability to military domains. Immediate action on warnings can mitigate long term deliverability problems.

September 2024 - SendGrid
Marketer view

Email marketer from Reddit User u/EmailPro shares that .mil domains often have strict filters and suggest providing recipients with the option to use a non-.mil address for subscriptions.

June 2024 - Reddit
Marketer view

Email marketer from Mailjet advises checking if your sending IP is blacklisted and ensuring proper authentication (SPF, DKIM, DMARC) are in place. Military domains often have stricter security policies.

October 2021 - Mailjet
Marketer view

Email marketer from Litmus recommends testing your email with various spam filters and email clients to identify and fix any issues that might be causing deliverability problems with .mil addresses.

March 2024 - Litmus
Marketer view

Email marketer from EmailOnAcid advises ensuring your email includes a plain text version, as some older .mil systems might require it. Having both HTML and plain text versions improves deliverability across different email clients.

February 2023 - EmailOnAcid
Marketer view

Email marketer from GlockApps suggests segmenting your list to isolate .mil addresses and sending a test email campaign. This helps identify specific deliverability issues related to those domains. Also important to ensure you aren't on any blocklists.

November 2023 - GlockApps
Marketer view

Marketer from Email Geeks shares that .mil only accepted plain text, no HTML, the last time they dealt with them.

October 2021 - Email Geeks

What the experts say
4Expert opinions

Deliverability issues with .mil email addresses stem from the unique, government-controlled nature of these domains. Blocks are often unrelated to spam and are due to the DoD's specific rules and policies, which differ significantly from commercial ISPs. Some .mil domains are not publicly accessible, and appealing decisions is typically not possible. Sending non-official content to .mil addresses is problematic, emphasizing the importance of recipient permission and ensuring content aligns with the domain's intended purpose. A platform was once asked to suppress all .mil emails, highlighting the potential need for alternative communication strategies. Feedback loops are beneficial.

Key opinions

  • Government Control: .mil domains are government-controlled with unique rules.
  • Blocks Unrelated to Spam: Blocks are often not related to typical spam indicators.
  • Limited Recourse: Appealing decisions is typically not possible.
  • Content Restrictions: Non-official content is problematic due to official use policies.
  • Network Restrictions: Some .mil domains are not publicly accessible.
  • Feedback Loops: Feedback loops are beneficial.

Key considerations

  • Alternative Addresses: Consider asking recipients to use non-.mil addresses.
  • Permission: Ensure recipients have granted explicit permission to receive email.
  • Content Alignment: Align content with the intended purpose of .mil addresses.
  • Understanding Policies: Understand and adhere to .mil specific policies and regulations.
Expert view

Expert from Email Geeks explains that .mil is a special case, and blocks are often unrelated to spam. Also, some .mil domains have been pulled from the public DNS and are only reachable from certain networks. Suggests asking recipients for a non-.mil address.

August 2023 - Email Geeks
Expert view

Expert from Email Geeks shares that a platform they worked at was asked to suppress all .mil emails at one point in the past.

August 2024 - Email Geeks
Expert view

Expert from Word to the Wise emphasizes the importance of understanding that .mil domains are government controlled and have different rules than commercial ISPs. Addresses are often for official use only, which makes sending non-official content problematic. Permission is key and working to ensure the recipients actually want the mail and are expecting it is important. Also make sure to have feedback loops enabled.

June 2024 - Word to the Wise
Expert view

Expert from Email Geeks explains that blocks are unrelated to spam because it’s DoD space, not commercial ISP space, and the rules are very different. You typically can’t appeal their decisions as they have no interest in facilitating the military using .mil addresses for non-military purposes.

December 2024 - Email Geeks

What the documentation says
5Technical articles

Resolving deliverability issues with .mil email addresses involves careful attention to sender reputation, email authentication, and content compliance. Microsoft's SmartScreen Filter and Cisco's SenderBase reputation services are utilized by .mil email servers to filter incoming mail. Therefore, monitoring and improving sender reputation is essential. Implementing DMARC, configuring SPF records correctly (RFC 7208), and utilizing DKIM signing are crucial steps to ensure email authentication and prevent spoofing, thereby improving deliverability to these stricter domains.

Key findings

  • SmartScreen Filter: Microsoft SmartScreen Filter can block emails to .mil addresses based on sender reputation or content.
  • SenderBase Reputation: Cisco SenderBase reputation is used by some .mil servers to filter mail.
  • DMARC Implementation: Proper DMARC implementation is essential for improving deliverability and preventing spoofing.
  • SPF Records: Correctly configured SPF records are critical for email authentication.
  • DKIM Signing: DKIM signing validates email authenticity and aids in deliverability.

Key considerations

  • Monitor Reputation: Continuously monitor and improve sender reputation with services like SmartScreen and SenderBase.
  • Content Compliance: Ensure email content complies with best practices to avoid triggering spam filters.
  • Authentication Setup: Implement DMARC, SPF, and DKIM correctly to authenticate emails.
  • Technical Specifications: Adhere to technical specifications outlined in RFC 7208 for SPF records.
Technical article

Documentation from DKIM.org details the process of implementing DKIM signing. DKIM signing validates the authenticity of your emails, which is essential for getting past the security measures implemented by .mil email servers.

September 2021 - DKIM.org
Technical article

Documentation from DMARC.org emphasizes the importance of DMARC implementation for improving deliverability. Proper DMARC configuration helps prevent email spoofing and ensures that your emails are authenticated, which is crucial for delivery to stricter domains like .mil.

January 2024 - DMARC.org
Technical article

Documentation from Cisco explains that SenderBase reputation services are used by some .mil email servers to filter incoming mail. A poor SenderBase reputation score can lead to deliverability issues. Suggests monitoring SenderBase reputation and taking steps to improve it.

July 2024 - Cisco
Technical article

Documentation from RFC Editor (RFC 7208) describes the technical specifications for SPF records. Ensuring a correctly configured SPF record is critical for authenticating your emails and preventing them from being flagged as spam, which is essential for delivery to .mil addresses.

April 2023 - RFC Editor
Technical article

Documentation from Microsoft Docs explains that the SmartScreen Filter in Outlook can block emails to .mil addresses if the sender's IP address has a poor reputation or the email content triggers spam filters. Suggests monitoring sender reputation and ensuring email content is compliant with best practices.

March 2022 - Microsoft Docs