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DNSMedium PriorityPro

SPF Lookup Limit

SPF records are limited to 10 DNS lookups per RFC 7208. Exceeding this limit causes SPF validation failures and email delivery issues.

Why It Matters

When SPF exceeds 10 lookups, receiving mail servers return PermError, causing legitimate emails to fail SPF checks. This can result in emails being rejected or marked as spam.

How We Check

We recursively resolve your SPF record, counting DNS lookups from include, a, mx, ptr, exists, and redirect mechanisms to verify compliance with the 10-lookup limit.

How to Fix

Flatten SPF includes by replacing them with direct IP ranges. Remove unused mechanisms. Consider using SPF macro syntax. Use tools like dmarcian or MXToolbox to monitor lookup count.

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