Summary
Gmail SPF errors arise from several sources, including DNS issues, incorrect SPF syntax, exceeding DNS lookup limits, unauthorized sending servers, use of third-party senders not included in the SPF record, IP address changes, and forwarding. Fixing these errors involves addressing DNS issues, using SPF validators for syntax correction, optimizing DNS lookups with SPF flattening, including all authorized sending sources (including third-party senders) in the SPF record, updating SPF records after IP changes, using SRS for forwarding issues, properly configuring SPF records including 'hard fails', and leveraging tools like dmarcian's SPF Surveyor for visualization.
Key findings
- DNS Problems: DNS server issues or incorrect DNS settings can lead to SPF failures.
- Syntax Errors: Incorrect syntax in the SPF record is a common cause of failures.
- Lookup Limits: Exceeding the 10 DNS lookup limit in SPF records triggers errors.
- Unauthorized Servers: SPF failures occur when the sending server isn't authorized by the SPF record.
- Third-Party Senders: Using third-party senders without including them in the SPF record causes failures.
- IP Changes: SPF records not updated after IP address changes will cause authentication to fail.
- Forwarding Issues: Email forwarding can break SPF authentication.
- Complexity of Configuration: The complexity of SPF records and their configurations can cause misconfiguration
Key considerations
- Check DNS: Verify DNS settings are correct and DNS servers are functioning properly.
- Validate Syntax: Use SPF validators to check for and correct syntax errors.
- Optimize Lookups: Employ SPF flattening or carefully manage include mechanisms to avoid exceeding lookup limits.
- Include All Sources: Ensure all authorized sending sources, including third-party senders, are in the SPF record.
- Update Records: Update SPF records whenever there are changes to sending server IP addresses.
- Implement SRS: Use Sender Rewriting Scheme (SRS) to handle forwarding issues.
- Configure Correctly: Ensure hard fails are used to reduce spoofing, and that all IP addresses are correctly entered
- Visualize SPF Record: Use tools like dmarcian's SPF Surveyor to visualize and understand your SPF record.
What email marketers say
10 marketer opinions
Gmail SPF errors can arise from various issues, including DNS problems, incorrect SPF record syntax, exceeding DNS lookup limits, using third-party senders without proper SPF inclusion, IP address changes, and forwarding. Solutions involve correcting DNS configurations, validating SPF syntax, optimizing include mechanisms with SPF flattening, adding third-party senders to SPF records, updating SPF records after IP changes, implementing SRS for forwarding, and utilizing online SPF validation tools.
Key opinions
- DNS Issues: DNS server problems, such as holding outdated zone information, can cause SPF failures.
- SPF Syntax Errors: Incorrect syntax in the SPF record, like missing quotes or incorrect mechanisms, can lead to SPF failures.
- DNS Lookup Limits: Exceeding the 10 DNS lookup limit in SPF records can trigger SPF failures.
- Third-Party Senders: Using third-party email senders not included in the SPF record causes SPF failures.
- IP Address Changes: SPF failures can occur when sending server IP addresses change and the SPF record is not updated.
- Forwarding Issues: Email forwarding can break SPF authentication if not handled correctly.
Key considerations
- Validate SPF Record: Regularly validate the SPF record for correct syntax and ensure all sending sources are included.
- Optimize DNS Lookups: Use SPF flattening or limit include mechanisms to avoid exceeding the DNS lookup limit.
- Incorporate Third-Party Senders: Add include mechanisms for all authorized third-party email senders to the SPF record.
- Update SPF After Changes: Update the SPF record whenever there are changes to sending server IP addresses.
- Implement SRS: Consider implementing Sender Rewriting Scheme (SRS) to handle forwarding issues.
- Use SPF Testing Tools: Utilize online tools to test SPF records and identify potential problems.
Marketer view
Email marketer from MailerLite explains to ensure you are checking your SPF records are valid using online validation tools.
10 Apr 2025 - MailerLite
Marketer view
Email marketer from Email Geeks explains that the Gmail error message related to SPF was due to a DNS server issue holding the zone information for the corporate email servers.
11 Feb 2024 - Email Geeks
What the experts say
2 expert opinions
SPF errors in Gmail can stem from complex SPF configurations and issues related to email forwarding. It's advised to visualize and understand your SPF record with tools like dmarcian's SPF Surveyor. Furthermore, email forwarding often breaks SPF, necessitating the implementation of SRS (Sender Rewriting Scheme) to ensure successful authentication.
Key opinions
- SPF Configuration Complexity: Complex SPF configurations, particularly with multiple sending sources, can lead to SPF errors.
- Forwarding Issues: Email forwarding is a common cause of SPF failures.
Key considerations
- Visualize SPF Record: Use tools like dmarcian's SPF Surveyor to visualize and understand your SPF record.
- Implement SRS: Implement Sender Rewriting Scheme (SRS) to handle forwarding issues and ensure SPF authentication passes.
Expert view
Expert from Spam Resource explains that SPF configuration can be complex, especially with multiple sending sources. He suggests utilizing a tool like dmarcian's SPF Surveyor to visualize and understand your SPF record and identify potential issues.
16 May 2024 - Spam Resource
Expert view
Expert from Word to the Wise shares that forwarding is a common cause of SPF failures. She recommends implementing SRS (Sender Rewriting Scheme) to ensure that SPF authentication passes even when emails are forwarded.
16 May 2025 - Word to the Wise
What the documentation says
4 technical articles
Gmail SPF errors occur when the sending server isn't authorized by the domain's SPF record. Reasons include incorrect SPF syntax, exceeding DNS lookup limits, omitting sending IPs/domains, and forwarding. Solutions involve correct SPF configuration with all authorized sources, using SPF checkers to identify errors, SPF flattening or SRS to address forwarding, and always ending with a hard fail while including all possible sending IP addresses.
Key findings
- Unauthorized Sending Server: SPF failures happen when the sending server is not authorized to send email on behalf of the domain, according to the SPF record.
- Incorrect SPF Syntax: Incorrect SPF record syntax can cause SPF failures.
- DNS Lookup Limit: Exceeding the DNS lookup limit in the SPF record can lead to SPF failures.
- Missing IPs/Domains: Not including all sending IPs and domains in the SPF record results in SPF failures.
- Forwarding Breaks SPF: Email forwarding can break SPF authentication.
Key considerations
- Correct SPF Configuration: Ensure the SPF record is correctly configured to include all authorized sending sources.
- Use SPF Checker: Use an SPF record checker to identify and correct any errors in the SPF record.
- Address Forwarding Issues: Use SPF flattening or Sender Rewriting Scheme (SRS) to address forwarding issues.
- Include All IPs: Make sure to include all possible sending IP addresses in your SPF record.
- Hard Fail: Always end with a hard fail in your SPF record.
Technical article
Documentation from Microsoft explains that to create SPF records correctly you must consider what you are including, always end with a hard fail and make sure to include all possible sending IP addresses.
28 Jan 2023 - Microsoft
Technical article
Documentation from Valimail explains that SPF failures can happen due to various reasons, including incorrect SPF record syntax, exceeding the DNS lookup limit, or not including all sending IPs/domains. They recommend using an SPF record checker to identify and correct errors.
23 Dec 2024 - Valimail
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