SPF

Sender Policy Framework: syntax, DNS lookup limits, permerror, and common misconfigurations.

Featured articles

SPF PermError explained
SPF PermError means the SPF record is invalid and cannot be evaluated correctly by receiving mail …
SPF Permerror: Too Many DNS Lookups
SPF permerror usually happens when your SPF record exceeds the maximum DNS lookup limit. Once the …
What is SPF?
SPF helps receiving mail servers verify which systems are allowed to send email for your domain.

All SPF articles

SPF PermError explained
SPF PermError means the SPF record is invalid and cannot be evaluated correctly by receiving mail …
SPF Permerror: Too Many DNS Lookups
SPF permerror usually happens when your SPF record exceeds the maximum DNS lookup limit. Once the …
What is SPF?
SPF helps receiving mail servers verify which systems are allowed to send email for your domain.
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Related topics

Email Authentication
How SPF, DKIM, and DMARC work together to prove an email really came from your domain.
DKIM
DomainKeys Identified Mail: selectors, signing, alignment, and key rotation.
DMARC
DMARC policies, alignment, and aggregate/forensic reporting.
DNS
The DNS record types and concepts email authentication and delivery depend on.
SMTP
SMTP transport, STARTTLS, MTA-STS, and TLS reporting.
Deliverability
Why legitimate email ends up in spam, and how to keep it out of it.
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