About this tool. SPF is a DNS record listing every service allowed to send email as your domain. Broken or duplicate SPF gets your mail junked. This check validates the record, counts the 10-lookup limit that silently breaks SPF, and names the senders it recognizes.
Ten signals decide whether your mail arrives. You just checked one.
SPF names who may send as you. It cannot say whether the message was altered on the way, and it cannot tell a receiver what to do when the check fails, which is what DKIM and DMARC are for.
- SPF, DKIM, DMARC, MX and blocklist status, graded A to F in one pass
- Every problem written out in plain English, with the record to publish
- Saved under Reports, so you can re-run it and see what changed
- One domain watched against the blocklists daily
Run the full checkup free
No card, and nothing to cancel.
How to read your SPF record
- SPF is a single DNS TXT record listing every server allowed to send mail as your domain. We decode each mechanism in plain English.
- Watch the DNS lookup count. SPF is limited to 10 lookups. Go over and it fails, no matter how correct the rest is.
- The ending matters: -all is a hard fail (strict), ~all is a soft fail (lenient), and +all is dangerous and should never be used.
Common problems and how to fix them
SPF passes some places and fails others
You likely exceed the 10-lookup limit or have two SPF records. Flatten includes you do not need and merge into one record.
A vendor's mail is being rejected
Add that vendor's include or IP to your single SPF record. Do not create a second SPF record.
Common questions.What is an SPF record?
A DNS TXT record that lists which mail servers are authorized to send email using your domain.
What is the SPF 10-lookup limit?
SPF may trigger at most 10 DNS lookups while evaluating. Exceeding it causes a permerror and SPF fails, so keep includes lean.
Should I use -all or ~all?
-all (hard fail) is stronger and preferred once you are confident every legitimate sender is listed. ~all (soft fail) is a safer starting point while you verify.