About SPF Flattening

SPF Flattening is an independent educational resource dedicated to one stubborn email-authentication problem: the SPF 10-lookup limit and the permerror it causes.

Sender Policy Framework is simple in theory and painful in practice. The moment a business runs a mailbox provider plus a CRM plus a marketing tool, nested provider includes quietly push the record past its lookup budget — and email starts failing authentication with no obvious cause. We explain, in plain language and with real records, what’s happening and how to fix it.

What we cover

• SPF flattening and macros — the two ways to get under the limit for good.
• The 10-lookup limit, permerror, and other SPF results.
• Provider-specific setup guides for the services that most often stack up lookups.

Our recommendation

Where a tool or service would genuinely help, we recommend the approach we consider most reliable — a managed, self-healing record that stays under the limit automatically. We aim to be accurate and practical; always verify DNS changes against your own environment before applying them in production.