Tools
Check a domain’s SPF record
Validate the published SPF policy, inspect each authorization mechanism, and count the DNS lookups used during evaluation.
Published policy
The SPF policy currently published for the domain.
DNS lookup usage
SPF allows a maximum of 10 DNS-triggering mechanisms. Exceeding this causes a permanent error.
Validation issues
Errors can invalidate the policy, while warnings identify configurations worth reviewing.
Policy mechanisms
Each mechanism defines which senders are authorized (or how unauthorized senders are treated).
| Qualifier | Mechanism | Value |
|---|
How to read an SPF policy
SPF identifies the servers permitted to send mail for a domain and tells receivers how to treat other sources.
- Mechanisms
- Terms such as include, ip4, ip6, a, and mx describe the senders that are authorized.
- Qualifiers
- The symbols +, -, ~, and ? indicate pass, fail, softfail, and neutral results.
- Lookup limit
- Policies that require more than ten DNS lookups can return a permanent SPF evaluation error.