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Q & A Email Authentication · August 5, 2026

What does 'SPF exceeds 10 DNS lookups' mean?

SPF evaluation is limited to 10 DNS lookups by RFC 7208. Each include:, a:, and mx: mechanism triggers a lookup. If your SPF chain exceeds 10, receivers return a PermError which many treat as a hard failure. Fix by replacing include: mechanisms with explicit ip4:/ip6: ranges (SPF flattening), or by removing services you no longer use.

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How to Check Email Authentication (SPF, DKIM, DMARC)
DomainScan's email authentication report checks your SPF, DKIM, and DMARC records in one pass, identifies misconfigurations, and explains what each finding means for your email deliverability and spoofing protection.
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