Summary
Consolidating SPF records efficiently requires adhering to the 10 DNS lookup limit mandated by services like Google Workspace, and understanding SPF syntax based on RFC 7208. Employing techniques such as SPF flattening, where 'include' statements are replaced with actual IP addresses (Cloudflare), and utilizing 'ip4' and 'ip6' definitions instead of 'includes' (AuthSMTP) can reduce lookups. DMARC monitoring provides valuable insights into SPF failures, allowing for a more targeted consolidation strategy (EasyDMARC). Tools like autospf.com (Email Geeks), SPF record checkers (GlockApps), and dedicated SPF management solutions (Mailhardener) automate the consolidation and maintenance. Remember that there should only be one SPF record (MXToolbox). Maintain records by removing old services (Word to the Wise). Finally, be aware of how SPF interacts with email forwarding (Spam Resource).
Key findings
- Lookup Limit: SPF records cannot exceed 10 DNS lookups.
- SPF Flattening: Reduces DNS lookups by replacing 'include' statements with IPs.
- DMARC Integration: DMARC monitoring identifies SPF failures for targeted action.
- Single Record: Only one SPF record is allowed; combine includes in one TXT record.
- Multiple Tools: Many tools exist to help manage and maintain SPF records, both paid and free. autospf.com, SPF Record checkers, SPF aggregation services.
Key considerations
- Regular Maintenance: Regularly update and remove outdated entries in the SPF record.
- Forwarding Implications: Consider the impact of SPF on legitimate email forwarding.
- Automation: Leverage automated tools for dynamic updates and easier maintenance.
- Include Scrutiny: Carefully evaluate each 'include' statement to avoid unnecessary lookups; only add domains that send on behalf of your domain.
- Dynamic IP Changes: Confirm the tool regularly checks include/DNS lookups, as IP blocks are added and removed periodically.
What email marketers say
9 marketer opinions
Consolidating SPF records is crucial for maintaining email deliverability and avoiding SPF validation failures due to exceeding the 10 DNS lookup limit. Best practices include regularly checking and updating SPF records, identifying and removing unnecessary include statements, and ensuring the tool used regularly checks include/DNS lookups. Tools such as SPF flatteners, SPF record checkers, and dedicated SPF management solutions automate the process and provide insights through DMARC reports. Manual consolidation involves copying IP addresses from included domains, but automated tools offer dynamic updates. Crucially, there should only be one SPF TXT record, combining all necessary information.
Key opinions
- Lookup Limit: SPF records must not exceed 10 DNS lookups.
- Automated Tools: Dedicated SPF management tools automate flattening and maintenance.
- DMARC Insights: DMARC monitoring provides insights into SPF failures.
- Single Record: You can only have 1 SPF record.
Key considerations
- Regular Checks: Ensure tools regularly check include/DNS lookups.
- Unnecessary Includes: Identify and remove unnecessary include statements.
- Manual vs. Auto: Consider the benefits of automated tools for dynamic updates.
- SPF syntax: Ensure the SPF TXT record has correct syntax.
Marketer view
Email marketer from GlockApps mentions using SPF record checker tools to identify syntax errors, exceeding lookup limits, and other issues that can impact email deliverability. Regularly check SPF to identify areas that need improvement.
21 Jan 2023 - GlockApps
Marketer view
Email marketer from StackExchange Super User talks about SPF best practices - specifically only add domains that send on behalf of your domain, and ensure you are only using the required includes
27 Jan 2024 - StackExchange
What the experts say
3 expert opinions
Consolidating SPF records involves using tools like autospf.com for the task. Maintaining up-to-date SPF records and removing old entries is essential. Furthermore, consider SPF's impact on email forwarding; SPF checks might fail if the forwarder isn't authorized for the original sender's domain.
Key opinions
- Tool Recommendation: autospf.com is suggested as a useful tool for SPF consolidation.
- Forwarding Issues: SPF can cause issues with email forwarding due to authentication failures.
- Record Maintenance: Keeping SPF records current and removing old entries improves deliverability.
Key considerations
- Forwarding Impact: Assess how SPF changes might affect legitimate email forwarding.
- Regular Review: Include SPF record review in routine deliverability tasks.
- Tool Suitability: Evaluate if the SPF consolidation tool meets your specific needs.
Expert view
Expert from Spam Resource explains that SPF can cause problems with forwarding because when someone forwards mail, it looks like it's coming from the forwarder, not the original sender, and the SPF check will fail if the forwarder isn't authorized to send mail for the original sender's domain. This isn't directly SPF consolidation, but is vital when consolidating SPF records to ensure legitimate forwarding continues.
2 Jun 2024 - Spam Resource
Expert view
Expert from Word to the Wise highlights the importance of maintaining your SPF records up-to-date and removing old entries when you stop using a service. They advise regularly reviewing SPF records as part of regular deliverability tasks.
6 Mar 2024 - Word to the Wise
What the documentation says
4 technical articles
Consolidating SPF records effectively involves understanding the limitations and syntax of SPF as defined in RFC 7208. A key limitation is the 10 DNS lookup limit imposed by Google Workspace. SPF flattening, as explained by Cloudflare, helps mitigate this by replacing 'include' statements with IP addresses. Additionally, AuthSMTP suggests using 'ip4' and 'ip6' definitions instead of includes to reduce DNS lookups.
Key findings
- Lookup Limit: SPF records must not exceed 10 DNS lookups.
- SPF Flattening: SPF flattening reduces DNS lookups by replacing 'include' statements.
- IP Definitions: Using 'ip4' and 'ip6' definitions can reduce DNS lookups.
- SPF Syntax: RFC 7208 defines SPF syntax and semantics.
Key considerations
- Lookup Optimization: Prioritize methods to reduce the number of DNS lookups.
- Syntax Compliance: Ensure SPF record syntax complies with RFC 7208.
- Flattening Implications: Understand the implications of SPF flattening on record maintenance.
- Address vs includes: Use ip4 and ip6 addresses to reduce the lookups by providers domain.
Technical article
Documentation from Google Workspace Admin Help explains the limitations of SPF records, stating that SPF records must not exceed 10 DNS lookups to prevent SPF validation failures.
5 Mar 2024 - Google Workspace Admin Help
Technical article
Documentation from RFC 7208 defines the syntax and semantics of the Sender Policy Framework (SPF). It outlines how SPF records should be structured, including the use of 'include' mechanisms, 'a', 'mx', and 'ip4/ip6' mechanisms.
18 Jun 2021 - RFC Editor
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