SPF Record Checker
Enter a domain to check its SPF record. See the full record, count DNS lookups, and verify compliance with the RFC 7208 limit of 10.
What is SPF?
SPF (Sender Policy Framework) is a DNS-based email authentication method. It lets domain owners specify which mail servers are authorized to send email on behalf of their domain.
SPF Record Syntax
An SPF record is a TXT record published in DNS. It always starts with v=spf1 followed by mechanisms and modifiers.
Common SPF Mechanisms
| Mechanism | DNS Lookup? | Description |
|---|---|---|
| include: | Yes | Check another domain's SPF record |
| a | Yes | Match domain's A records |
| mx | Yes | Match domain's MX records |
| ip4: / ip6: | No | Match specific IP addresses or ranges |
| redirect= | Yes | Use another domain's SPF record entirely |
| all | No | Match all (usually -all or ~all at the end) |
The 10 DNS Lookup Limit
RFC 7208 limits SPF records to 10 DNS lookups. Mechanisms like include:, a, mx, and redirect= each count as one lookup. Exceeding this limit causes SPF to return a permanent error (PermError), which can result in email delivery failures.
Use ip4: and ip6: mechanisms where possible — they do not count toward the lookup limit.