The modern handbook on SPF

SPF stands for Sender Policy Framework. Learn what it checks, how SPF records work, and how to validate your setup.

Discover which domain SPF checks against, understanding the roles of the Return-Path and HELO/EHLO domains in email authentication and deliverability.

Does your SPF domain match your From address? Learn how this impacts DMARC alignment and deliverability when sending emails with platforms like Marketo.

Learn how SPF a records impact DNS lookups and the 10-lookup limit. Optimize your records to prevent email authentication failures.

Learn to format SPF records, manage includes, and avoid the 10-lookup limit for better email deliverability. Use Suped for monitoring.

Learn the difference between ~all and -all in your SPF record. Understand how these mechanisms impact deliverability and spoofing protection with Suped.

Understand the SPF 10 DNS lookup limit, its impact on email deliverability, and how to optimize your records to maintain a healthy sender reputation.

Fix SPF records exceeding the 10 DNS lookup limit. Use Suped to flatten and optimize your SPF records for better email deliverability.

Learn when SPF flattening is needed to bypass the 10 DNS lookup limit and how to validate your SPF records for optimal email deliverability and security.

Align SPF with your domain to improve email deliverability. Use Suped to resolve alignment issues, avoid blocklist or blacklist placement, and boost reach.

Fix SPF alignment issues for Google Workspace alias domains. Improve email deliverability using DKIM and DMARC with Suped reporting.

Microsoft SPF TempError often comes from DNS timeouts. Learn how to find lookup chains, reduce SPF risk, and fix authentication.