All tools
SPF Record Lookup
Resolve a domain's SPF live: policy, authorised senders, and the DNS-lookup count against the limit of 10.
Why this exists
SPF allows at most 10 DNS-querying mechanisms; go over and receivers return PermError and mail can fail authentication. Includes nest, so the real count is rarely obvious from the raw record, and the all-qualifier policy is easy to miss.
How to use
- Type a domain (e.g. acme.com).
- The record is resolved recursively: each include/a/mx/redirect is counted and the policy (the all qualifier) is read out.
- A tree shows where the lookups go, with a red flag if it exceeds 10. For MX/DMARC/DKIM too, use the DNS Toolbox.
Look up an SPF record
Resolve the SPF record for any domain live: the policy (the all qualifier), every authorised sender, and the recursive DNS-lookup count against the limit of 10. Try salesforce.com or a tenant with lots of vendors, where heavily nested includes blow past the limit into PermError. For the full DNS picture (MX, DMARC, DKIM), use the DNS Toolbox.