How does SPF flattening affect email evaluation tools and are there alternatives?
Summary
What email marketers say10Marketer opinions
Email marketer from NeilPatel.com shares that SPF records should be optimized to avoid exceeding the DNS lookup limit. While flattening can help, carefully managing included domains and services is crucial to prevent deliverability issues, especially when using evaluation tools that may not handle complex SPF records well.
Email marketer from ZeroBounce points out the need to regularly validate SPF records. They further recommend monitoring deliverability metrics after any changes to SPF, including flattening, to verify effectiveness.
Email marketer from Mailgun promotes implementing DKIM to sign all outgoing emails. They indicate this offers superior email authentication and avoids SPF's DNS lookup limitations.
Email marketer from Sendgrid explains that while SPF flattening solves the DNS lookup issue, it is important to monitor the flattened record. If one of the included IP ranges changes, your SPF will need to be updated, which can take time to propagate.
Email marketer from SparkPost shares that DKIM offers an alternative to SPF flattening, providing authentication without DNS lookups. They also advise segmenting sending domains to distribute the SPF load and using monitoring tools to detect issues before they impact deliverability.
Email marketer from Reddit explains that SPF checkers can sometimes be inaccurate with complex records. They suggest using multiple checkers and manually verifying SPF records using `dig` commands to ensure accuracy before making changes.
Email marketer from EasyDMARC shares that SPF flattening may cause temporary deliverability issues due to DNS propagation delays. It is better to implement DKIM and monitor DMARC reports.
Email marketer from Mailjet explains that SPF flattening addresses the DNS lookup limit, but it may not resolve all evaluation issues. They suggest monitoring SPF records with tools like Mailjet's SPF record checker and switching to DKIM if problems persist, as DKIM authentication relies on cryptographic signatures rather than DNS lookups.
Email marketer from StackExchange shares that avoiding too many includes in the SPF is key to avoid exceeding DNS lookup limits. If needing multiple ESPs, using subdomains for each one could be better than including them all in the main domain.
Email marketer from GlockApps recommends using comprehensive deliverability testing tools. These can identify problems with SPF records and offer insights into how different email providers handle the email.
What the experts say6Expert opinions
Expert from Email Geeks shares that some checkers have trouble with macros and flatteners and automation in the SPF record. He suggests testing at Gmail and using the Kitterman SPF record checker.
Expert from Email Geeks explains that SPF macros are not handled well by some tools. His checker at tools.wordtothewise.com fails horribly on them.
Expert from Email Geeks suggests evaluating whether SPF flattening is truly necessary, questioning if too many unnecessary elements are included in the SPF record.
Expert from Spam Resource indicates carefully manage your SPF record to avoid DNS lookup issues. Using DKIM could be a good alternative, and to regularly evaluate and clean up your SPF entries.
Expert from Word to the Wise shares that SPF records have limitations, including a maximum number of DNS lookups. When these limits are exceeded, SPF authentication fails. Alternatives include DKIM, which doesn't rely on DNS lookups, and carefully managing includes within the SPF record.
Expert from Word to the Wise explains that some tools don't handle macros or SPF flattening correctly, which can lead to false negatives when testing. They suggest using multiple test tools or a manual verification.
What the documentation says5Technical articles
Documentation from Microsoft explains SPF best practices, including limiting the number of DNS lookups. They recommend using alternatives like DKIM and DMARC and monitoring SPF records for changes in included services.
Documentation from Google explains that some evaluation tools may not fully support all SPF syntax or macro expansions, which could lead to false positives. It is recommended to test SPF records using multiple reputable tools and to monitor email deliverability to ensure proper configuration.
Documentation from RFC Editor explains that SPF implementations have limitations in processing macros and complex SPF records. Flattening aims to reduce complexity, but some tools may still misinterpret expanded macros or have limitations on DNS lookup counts, leading to evaluation errors.
Documentation from IETF emphasizes the importance of adhering to SPF standards but also indicates the challenges associated with DNS lookup limits and macro evaluations. It suggests implementing DKIM and DMARC for robust email authentication.
Documentation from DMARC.org suggests that SPF alone may not be sufficient for robust email authentication. It recommends implementing DKIM alongside SPF and aligning them using DMARC. DKIM offers a different authentication method that isn't subject to the same DNS lookup limitations as SPF, providing a more resilient approach to email deliverability.