SPF checker
An SPF checker reads the TXT record that lists which servers may send email as your domain.
On a course or coaching domain, a fail usually means that record is missing, there is more than one, it ends in +all, or it needs more than 10 DNS lookups.
Nothing is stored. The check runs in your browser against public DNS. CourseSignal does not keep the domain you look up.
What an SPF record is
SPF is one TXT record at the root of the domain, starting with v=spf1. It names the services allowed to send as you, then ends in ~all (soft fail) or -all (hard fail). A second SPF record, or no record at all, means receivers cannot use SPF to decide who may send as you.
The checker on this page still reads SPF, DKIM, DMARC and MX together. Other free DNS tools publish the raw record. Use this one when the domain sends course or coaching email and you want the SPF result in plain language.
How to read a fail
- No SPF record. There is no TXT record starting with v=spf1. Add one record that lists every service that sends as you, and end it with ~all or -all.
- More than one SPF record. SPF allows one v=spf1 record. Two or more make receivers treat SPF as a permanent error. Merge them into a single record.
- Ends in +all. +all, or a bare all, says any server may send as you. Change it to ~all while you test, or -all once every sender is listed.
- More than 10 DNS lookups. include, a, mx, ptr, exists and redirect each cost a lookup, and nested includes count. Over 10, SPF fails even if the text looks right. Remove includes you no longer use.
Then work through the send, not only the DNS
Authentication is step one. The CourseSignal Email Deliverability Checklist walks through SPF, DKIM and DMARC, list hygiene, warm-up and a pre-send test for course and coaching email. It does not promise inbox placement.
Advert Paid download from CourseSignal.Sold and delivered by Payhip. More detail on the checklist page.
FAQ
What does an SPF fail mean?
In this checker, a fail means the record is missing, duplicated, ends in +all, or is over the 10-lookup limit. It does not by itself prove a campaign went to the spam folder.
Can I publish two SPF records?
No. Keep a single v=spf1 TXT record and put every sending service in that one record.
Does an SPF pass mean the email will reach the inbox?
No. SPF only answers whether the sending server is on your list. DKIM, DMARC, reputation, the list and the content still matter.
Is this the only SPF checker?
No. Plenty of free DNS tools look up SPF. This page is written for people who send course and coaching email, and it explains the fail before you edit DNS.
Related: Email authentication checker · DMARC checker · DKIM checker · Check if email goes to spam · Deliverability testing tools · Deliverability checklist.