What tools or scripts can fix common DKIM problems like formatting errors or length issues?

Summary

Common DKIM problems include syntax errors, formatting issues, and key length limitations. Experts and documentation suggest various tools for prevention and diagnosis. Online DKIM record generators and validators help avoid and identify syntax errors. For key length problems exceeding DNS limits, options include splitting the record or using providers that support longer TXT records. Continuously monitoring DKIM key usage and validity through DMARC reporting tools and `opendkim-testkey` helps detect and resolve issues, including the importance of rotating keys. The underlying issue is often human error due to copy-pasting, therefore improved automation to improve accuracy would be useful.

Key findings

  • Diverse Problems: DKIM issues involve syntax errors, formatting, and key length.
  • Syntax Tools: Online validators and generators help with syntax issues.
  • Length Solutions: Split records or use DNS providers that allow larger TXT entries to address length issues.
  • Monitoring Is Key: Use DMARC reporting for key validity and usage, as well as to determine if rotation needs to occur.
  • Human Error Cause: Manual entry with copy and paste can create issues, so more automation is needed.

Key considerations

  • Verify Copy/Paste: Review DKIM records copied from source for special characters and correctness.
  • Consider Automation: Use tools to automate record setup, and remove human-error.
  • Know Your DNS: Make sure your DNS provider supports large records before starting.
  • Keep rotating keys: Rotate the keys to maximize security.

What email marketers say
8Marketer opinions

Common DKIM problems often involve errors in the DKIM public key's value, such as incorrect syntax, formatting errors, or exceeding length limits. While dedicated scripts to 'fix' these errors are rare, several tools and strategies can prevent or diagnose them. Online DKIM record generators, validators, and debugging tools can identify syntax errors and misconfigurations. For length issues, splitting the DKIM record or ensuring DNS provider support for longer TXT records are recommended. Monitoring DKIM key usage via DMARC reports also helps maintain validity.

Key opinions

  • Problem Variety: DKIM issues range from formatting errors (syntax, special characters) to key length limitations.
  • Preventative Tools: Online DKIM record generators can prevent syntax errors during record creation.
  • Diagnostic Tools: Online validators and debuggers help identify and pinpoint existing DKIM issues.
  • Length Solutions: Splitting DKIM records or using DNS providers with longer TXT record support addresses key length problems.
  • Monitoring Importance: DMARC reports are helpful for ongoing monitoring of DKIM key usage and detecting potential problems.

Key considerations

  • Human Error: Manual copying and pasting of DKIM records is prone to human error; consider automation where possible.
  • DNS Support: Verify that your DNS provider supports long TXT records or multiple record concatenation if needed.
  • Tool Choice: Different tools address different issues; use a combination for comprehensive DKIM management.
  • Key Rotation: Implement a DKIM key rotation strategy and monitor regularly to maintain security and prevent key compromise.
Marketer view

Email marketer from Reddit user EmailGuru42 shares that online DKIM record generators can help avoid formatting errors when creating DKIM records. These tools automatically generate the correct syntax, reducing the risk of human error.

April 2024 - Reddit
Marketer view

Email marketer from SparkPost explains that they use a tool to set up DKIM records, the tool makes the set up of the record easier.

May 2024 - SparkPost
Marketer view

Email marketer from dmarcian shares that they provide tools to test and check your DKIM key. They explain that the key has to be a certain size, and that their tool helps with checking that.

April 2024 - dmarcian
Marketer view

Email marketer from EmailDudes Forum user DKIMfixer recommends using online DKIM debugging tools to check the DKIM signature of sent emails. These tools analyze the email headers and DKIM signature to identify any issues that might be causing authentication failures.

April 2021 - EmailDudes Forum
Marketer view

Marketer from Email Geeks shares that common DKIM problems are variations on "errors in the value part of the published DKIM public key" and is unaware of any scripts to fix these, but there are ongoing conversations about preventing them. These conversations focus on the theory that having users copy and paste the DKIM public key is a recipe for human error and that removing the humans from the process might be a good thing.

July 2023 - Email Geeks
Marketer view

Email marketer from MXToolbox shares that their DKIM record lookup tool can identify issues such as invalid syntax, incorrect key length, and other misconfigurations. They also share that it will allow you to quickly validate if the key is correctly set up in the DNS record.

March 2021 - MXToolbox
Marketer view

Email marketer from Stack Overflow user CodingNewbie shares that when dealing with DKIM key length issues, particularly exceeding the 255-character limit for DNS records, using a shortened key is not advisable. Instead, he suggests ensuring that the DNS provider supports TXT records longer than 255 characters or splitting the DKIM record into multiple TXT records, concatenating them in the correct order. He also advises consulting the DNS provider's documentation for the specific method.

July 2021 - Stack Overflow
Marketer view

Email marketer from Email Geeks shares that common DKIM problems include DKIM keys being too long which causes minimum concatenation to get within 255, other formatting errors, base64 errors, line breaks or special characters to be stripped out, too many quotes.

October 2023 - Email Geeks

What the experts say
2Expert opinions

Experts highlight key areas for managing DKIM problems. Incorrect key syntax, often due to errors during copy-pasting into DNS records, is a common issue best addressed using online DKIM validators. Furthermore, continuous monitoring of DKIM key usage and validity through DMARC reporting tools is crucial for identifying and resolving issues, especially ensuring keys are rotated as needed for security.

Key opinions

  • Syntax Errors: Incorrect DKIM key syntax is a frequent problem, often resulting from copy-paste errors.
  • Validation Tools: Online DKIM validators can help identify and correct syntax errors.
  • Monitoring Importance: Continuous monitoring of DKIM key usage is essential for identifying potential problems.
  • DMARC Reporting: DMARC reporting tools are valuable for identifying DKIM-related issues.
  • Key Rotation: Ensuring DKIM keys are rotated regularly is necessary for security.

Key considerations

  • Copy-Paste Errors: Carefully review the DKIM record after copy-pasting to ensure no hidden characters or line breaks are introduced.
  • Validator Usage: Utilize online DKIM validators to verify the accuracy of the DKIM record.
  • DMARC Implementation: Implement and monitor DMARC reports to proactively identify DKIM issues.
  • Rotation Strategy: Develop and implement a DKIM key rotation strategy for improved security.
Expert view

Expert from Spam Resource explains that one common issue is incorrect key syntax. He recommends using online DKIM validators, and ensuring that the copy and paste process for adding keys to DNS records doesn't introduce hidden characters or line breaks.

December 2024 - Spam Resource
Expert view

Expert from Word to the Wise emphasizes the importance of monitoring DKIM key usage and validity. They suggest using DMARC reporting tools to identify any DKIM-related issues and ensure keys are rotating as needed.

March 2022 - Word to the Wise

What the documentation says
4Technical articles

Documentation sources identify incorrect syntax as a primary DKIM issue. Online DKIM validators, the `dig` command, Google Admin Toolbox's DNS record checker, and `opendkim-testkey` are recommended tools for verifying DKIM key syntax, propagation, and overall validity. RFC6376 provides the foundational standards for DKIM implementations and troubleshooting.

Key findings

  • Syntax Matters: Incorrect syntax is a common cause of DKIM failure.
  • Validation Tools: Online validators, `dig`, and Google Admin Toolbox are useful for checking syntax.
  • Command Line Tool: `opendkim-testkey` is a command-line tool for key verification.
  • Standards Document: RFC6376 defines DKIM standards.

Key considerations

  • Tool Selection: Choose the appropriate tool based on the specific problem and technical expertise.
  • Standard Compliance: Ensure DKIM implementations adhere to RFC6376.
  • Propagation Checks: Verify DNS record propagation after making changes.
Technical article

Documentation from Google Workspace Admin Help responds to issues of DKIM failing due to formatting. It suggests using the `dig` command or Google Admin Toolbox's DNS record checker to verify the DKIM record's syntax and propagation. This helps identify any misconfigurations that might be causing authentication failures.

December 2024 - Google Workspace Admin Help
Technical article

Documentation from RFC6376 shares that the standards are set in this RFC. It defines the syntax and semantics of DKIM signatures and records, providing a reference for developers creating or troubleshooting DKIM implementations.

September 2023 - RFC6376
Technical article

Documentation from OpenDKIM explains that tools like `opendkim-testkey` can be used to verify DKIM keys and diagnose common issues. This command-line tool checks the key's validity and helps identify errors in the DKIM setup.

March 2025 - OpenDKIM
Technical article

Documentation from DKIM.org explains that a common DKIM problem is incorrect syntax. Tools like online DKIM validators can help identify and pinpoint syntax errors in the DKIM record. These validators check for missing semicolons, incorrect attribute-value pairs, and other structural issues that can cause DKIM to fail.

December 2024 - DKIM.org