Dealing with overstuffed SPF records exceeding the 10 DNS lookup limit requires a multi-faceted approach. Documentation highlights the importance of the limit and potential deliverability issues. Experts and marketers suggest options such as simplifying SPF records by removing unnecessary includes, relying on DKIM (and DMARC) as alternative authentication methods, employing SPF flattening (with careful maintenance), utilizing subdomains or dedicated sending domains, and regularly auditing/optimizing SPF records. Hosted SPF services and external authentication services can also resolve the lookup limit. The key is to ensure that the chosen methods are implemented correctly and maintained to achieve optimal email deliverability and authentication.
13 marketer opinions
When SPF records exceed the 10 DNS lookup limit, several options exist. These include relying solely on DKIM, employing SPF flattening (though this requires ongoing maintenance), using subdomains for different email streams, migrating to dedicated sending domains, regularly auditing and removing obsolete entries, and using external services to manage SPF and DKIM. Hosted SPF services, like those offered by Proofpoint, can also resolve lookup limits. It's generally advised to use SPF in conjunction with DKIM and DMARC for robust email authentication.
Marketer view
Email marketer from StackOverflow mentions using a dedicated sending domain or subdomain for email marketing. This allows for a simpler SPF record that only includes the necessary services for that specific sending domain, reducing the risk of exceeding the lookup limit.
10 Jul 2021 - StackOverflow
Marketer view
Email marketer from Reddit suggests migrating entirely to DKIM. If SPF is too difficult to manage, DKIM offers a robust alternative for authentication without the DNS lookup limitations of SPF. It involves digitally signing emails, which is verified by the receiving server.
3 Jul 2022 - Reddit
4 expert opinions
Experts suggest several approaches to handling overstuffed SPF records exceeding DNS lookup limits. These include reviewing and optimizing existing records by removing obsolete entries and consolidating includes, using dedicated domains for the 5321.from, and taking the opportunity to create a streamlined SPF record when migrating to a new ESP. Ignoring the issue, though some ISPs are forgiving, is not recommended.
Expert view
Expert from Word to the Wise talks about migrating to a new ESP, that is a good opportunity to address the SPF record. Work with the new ESP to create a lean and optimized SPF record that only includes the necessary sending sources.
14 Dec 2024 - Word to the Wise
Expert view
Expert from Email Geeks explains that a significant problem is people publishing SPF for the wrong domain and ESPs providing bad guidance, recommending dedicated domains for the 5321.from.
3 Oct 2024 - Email Geeks
4 technical articles
Documentation emphasizes the 10 DNS lookup limit in SPF records, highlighting potential deliverability issues if exceeded. Suggested solutions include simplifying SPF records by removing unnecessary includes, utilizing alternative authentication methods like DKIM, and ensuring proper SPF, DKIM, and DMARC configuration and alignment. Utilizing DKIM can assist when SPF is problematic.
Technical article
Documentation from Microsoft answers that for Microsoft 365, it's essential to configure SPF, DKIM, and DMARC correctly. While SPF has its limits, combining it with DKIM can improve email deliverability and authentication. Ensure SPF is set up for all sending domains.
4 Dec 2021 - Microsoft
Technical article
Documentation from Google Workspace Admin Help explains that SPF records have a limit of 10 DNS lookups. Exceeding this limit can cause SPF checks to fail, impacting email deliverability. They suggest simplifying SPF records by removing unnecessary includes or using alternative authentication methods like DKIM.
28 Dec 2023 - Google Workspace Admin Help
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