Validate Your Email Sending Policy
SPF Record Checker
Look up and parse any domain's SPF record — analyze mechanisms, qualifiers, DNS lookup count, and get warnings about common issues.
Frequently Asked Questions
What is SPF?
SPF (Sender Policy Framework) is an email authentication protocol that specifies which mail servers are authorized to send email on behalf of your domain. It's published as a TXT record in DNS starting with 'v=spf1' and helps prevent email spoofing.
What does the 'all' mechanism mean in SPF?
The 'all' mechanism is a catch-all at the end of an SPF record. '-all' (hard fail) means reject unauthorized senders, '~all' (soft fail) means mark as suspicious, '?all' (neutral) takes no action, and '+all' (pass) allows everyone — which defeats the purpose of SPF.
Why is there a 10 DNS lookup limit?
RFC 7208 limits SPF evaluation to 10 DNS lookups (include, a, mx, ptr, exists, redirect) to prevent denial-of-service attacks and excessive DNS queries. Exceeding this limit causes SPF to return a 'permerror', which may cause email delivery failures.
What's the difference between -all and ~all?
'-all' (hard fail) instructs receivers to reject messages from unauthorized senders. '~all' (soft fail) marks them as suspicious but still delivers them. Hard fail provides stronger protection, but soft fail is safer during initial deployment.
Can I have multiple SPF records?
No. A domain must have at most one SPF record. Having multiple TXT records starting with 'v=spf1' causes a 'permerror' and SPF will fail. If you need to authorize multiple services, use the 'include' mechanism within a single record.
Complete Guide: How to Use the SPF Record Checker
Validate your domain's SPF (Sender Policy Framework) record to ensure legitimate email senders are authorized and spoofers are blocked. Our checker parses every SPF mechanism, counts DNS lookups (max 10 allowed), detects syntax errors, and verifies that all included domains resolve correctly.
Step-by-Step Instructions
- 1
Enter your domain
Type the domain to check (e.g., example.com). The tool retrieves the SPF TXT record starting with 'v=spf1'.
- 2
View parsed mechanisms
See each mechanism broken down: ip4/ip6 ranges, include references, a/mx lookups, and the all mechanism (qualifier: +, -, ~, ?).
- 3
Check DNS lookup count
SPF has a 10-lookup limit. The tool counts all 'include', 'a', 'mx', 'redirect', and 'exists' mechanisms against this limit.
- 4
Review errors and warnings
See syntax errors, missing mechanisms, excessive lookups, and deprecated features. Each issue includes a fix recommendation.
Common Use Cases
- ✓Email deliverability — ensure SPF doesn't block legitimate outbound email from your servers
- ✓Anti-spoofing — verify that SPF blocks unauthorized senders from using your domain
- ✓Migration — update SPF records when adding new email services (Google Workspace, SendGrid, etc.)
- ✓Troubleshooting — diagnose SPF-related email rejection or spam folder placement
- ✓Compliance — verify SPF meets organizational email authentication requirements
- ✓Optimization — reduce DNS lookups to stay under the 10-lookup limit
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