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
8 marketer 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.
16 May 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.
9 Jul 2024 - SparkPost
What the experts say
2 expert 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.
17 Mar 2025 - 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.
9 May 2025 - Word to the Wise
What the documentation says
4 technical 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.
14 Jan 2023 - 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.
6 Apr 2023 - RFC6376
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