Summary
The recurring 'DKIM=none' and 'SPF=none' status in email headers, leading to Outlook deliverability problems, stems from a multifaceted range of issues, primarily revolving around email authentication. These issues include: incorrect DNS configurations for SPF, DKIM, and DMARC records; SPF record syntax errors; exceeding the SPF DNS lookup limit; the sending server's IP not being authorized in the SPF record; poor sender or IP reputation; IP blacklisting; content being flagged as spam; and Microsoft's internal email processing quirks. Successfully addressing these challenges demands meticulous DNS record verification, adherence to SPF record syntax guidelines, ongoing monitoring and improvement of sender reputation, and vigilant blacklist checks, as well as reverse DNS setup on the sending IPs.
Key findings
- DNS Misconfiguration: Incorrect DNS configurations for SPF, DKIM, and DMARC are primary causes of authentication failure.
- SPF Record Issues: SPF failures often result from syntax errors, exceeding DNS lookup limits, or unauthorized IP addresses.
- Poor Reputation: Poor sender or IP reputation negatively impacts deliverability to Outlook.
- IP Blacklisting: IP addresses on blacklists are likely to be blocked by Outlook.
- DMARC Impact: Missing or misconfigured DMARC policies can negatively affect deliverability.
- Microsoft's Processes: Microsoft's internal email processing might temporarily show 'none' even if authentication passes.
- Reverse DNS: Correct setup of authentication on the sending domain and reverse DNS on sending IPs is crucial.
Key considerations
- Verify DNS Records: Thoroughly verify and correct SPF, DKIM, and DMARC records in DNS settings.
- Optimize SPF: Optimize SPF records to stay within the 10 DNS lookup limit.
- Monitor Reputation: Regularly monitor sender and IP reputation, and take steps to improve it.
- Check Blacklists: Check IP addresses against blacklists and request removal if listed.
- Implement Authentication: Implement and properly configure SPF, DKIM, and DMARC authentication.
- Avoid Warming Services: Avoid using warming services, as they are not recommended and may not align with deliverability best practices.
- Setup Reverse DNS: Setup correct reverse DNS on sending IPs to aid in authentication.
What email marketers say
9 marketer opinions
The 'DKIM=none' and 'SPF=none' status in email headers, coupled with Outlook deliverability issues, primarily indicates problems with email authentication setup. Key contributing factors include missing or misconfigured DNS records (SPF, DKIM, DMARC), exceeding SPF DNS lookup limits, IP blacklisting, poor sender reputation, and Microsoft's internal email processing. Addressing these issues requires careful DNS configuration, regular monitoring of sender reputation, and adherence to email deliverability best practices.
Key opinions
- DNS Configuration: Missing or misconfigured SPF, DKIM, and DMARC records are primary causes for authentication failures.
- SPF Limits: Exceeding SPF DNS lookup limits can lead to SPF failures.
- Sender Reputation: Poor sender reputation significantly impacts deliverability to Outlook.
- IP Blacklisting: IP addresses on blacklists will be blocked by Outlook.
- DMARC Impact: Failing SPF can impact DMARC even if DKIM is passing, which can cause deliverability issues.
- Propagation Delay: DNS record changes may take 24-48 hours to propagate, so test after waiting.
Key considerations
- DNS Verification: Thoroughly verify and correct SPF, DKIM, and DMARC records in DNS settings.
- Limit SPF Lookups: Optimize SPF records to stay within the 10 DNS lookup limit.
- Reputation Monitoring: Regularly monitor sender reputation and take steps to improve it (e.g., dedicated IP, consistent sending volume).
- Blacklist Checks: Check IP addresses against blacklists using tools like MXToolbox and request removal if listed.
- Authentication: Ensure all outgoing emails are properly authenticated with SPF, DKIM, and DMARC to improve deliverability and sender reputation.
- Warming Up: Consider warming up new IP addresses gradually to establish a positive sending reputation.
Marketer view
Email marketer from Mailgun Blog shares that to improve deliverability to Outlook, ensure your sending domain is properly authenticated with SPF, DKIM, and DMARC. Additionally, monitor your sender reputation and avoid sending spam-like content.
24 Nov 2022 - Mailgun Blog
Marketer view
Email marketer from EmailMarketingForum shares that the DKIM none could be caused by the DNS record not being properly propagated. Wait 24-48 hours after setting it up to confirm.
25 Nov 2021 - EmailMarketingForum
What the experts say
4 expert opinions
The appearance of 'DKIM=none' and 'SPF=none' in email headers, which is linked to Outlook deliverability issues, is often attributed to configuration problems related to email authentication protocols. The main factors consist of exceeding DNS lookup limits for SPF, syntax errors in the SPF record, the sending server's IP address not being authorised, and missing or misconfigured DMARC policy. Correct setup of authentication on the sending domain and reverse DNS on sending IPs is crucial.
Key opinions
- SPF Failures: SPF can fail due to exceeding the DNS lookup limit, incorrect syntax, or unauthorized IP addresses.
- DMARC Impact: Missing or misconfigured DMARC can negatively affect deliverability by not instructing receiving servers on how to handle failing authentication.
- Authentication Needed: Correctly configured DKIM, DMARC, and reverse DNS are essential for proper authentication.
Key considerations
- Configure DKIM and DMARC: Implement DKIM and DMARC to enhance email security and deliverability.
- Test SPF Records: Ensure SPF records are correctly configured and tested to avoid failures.
- Implement Reverse DNS: Setup correct reverse DNS on sending IPs to aid in authentication.
Expert view
Expert from Spam Resource explains that SPF failures (showing 'none') can be due to multiple issues, including exceeding the 10 DNS lookup limit, incorrect syntax in the SPF record, or the sending server's IP address not being authorized in the SPF record. Properly configuring and testing the SPF record is crucial.
13 Oct 2022 - Spam Resource
Expert view
Expert from Email Geeks suggests configuring DKIM and DMARC and shares links to directions and a testing tool.
26 Sep 2022 - Email Geeks
What the documentation says
5 technical articles
The issue of 'DKIM=none' and 'SPF=none' in email headers, leading to Outlook deliverability problems, is commonly attributed to DNS configuration errors and SPF record syntax issues. Incorrect DKIM TXT records, SPF record syntax errors, exceeding the 10 DNS lookup limit for SPF, domain reputation, IP blacklisting, and content being flagged as spam are all contributing factors. Troubleshooting involves ensuring DNS records are correctly configured, validating SPF syntax, and monitoring domain and IP reputation.
Key findings
- DKIM Configuration: DKIM failures often result from incorrect DNS configuration, especially with TXT records and the proper selector.
- SPF Configuration: SPF failures are frequently caused by syntax errors or the sending server's IP not being included in the SPF record.
- Reputation & Blacklisting: Deliverability issues to Outlook can stem from poor domain reputation or IP addresses being blacklisted.
- SPF Syntax: SPF records must be syntactically correct, avoiding common errors such as incorrect use of mechanisms or incorrect formatting.
- SPF Limits: SPF syntax errors include exceeding the 10 DNS lookup limit, incorrect use of modifiers, or having multiple SPF records
Key considerations
- Correct DNS Records: Ensure DKIM and SPF TXT records are correctly published in DNS with the proper syntax and selector.
- Validate SPF Syntax: Use validation tools to check SPF records for syntax errors and ensure the sending server's IP is authorized.
- Monitor Reputation: Monitor domain and IP reputation, and address any issues that could lead to blacklisting or spam flagging.
- Use Postmaster Tools: Use Google Postmaster Tools to help diagnose deliverability issues.
Technical article
Documentation from Microsoft Learn explains that DKIM failures (showing as 'none') often stem from incorrect DNS configuration, particularly related to TXT records. Ensure the DKIM record is published correctly with the proper selector.
8 May 2022 - Microsoft Learn
Technical article
Documentation from DMARC.org explains that SPF failures leading to a 'none' result in headers usually indicate an issue with the SPF record's syntax or that the sending server's IP address isn't included in the allowed list of sending sources in the SPF record.
4 Feb 2025 - DMARC.org
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