Use this free SPF checker to look up your domain's SPF record, validate its syntax, and find errors that send your emails to spam.
An SPF record checker validates your domain's Sender Policy Framework configuration by querying DNS records and checking for proper syntax, multiple records, and authentication issues that could impact email deliverability.
Quickly check if your domain has a valid SPF record and identify any configuration issues that could affect email delivery.
Get comprehensive analysis of your SPF record including syntax validation, duplicate detection, and specific error identification.
Properly configured SPF records help prevent email spoofing and improve your domain reputation with email providers.
Email authentication through DNS records
When an email arrives, the receiving server checks the sender's domain DNS records for an SPF record that lists authorized mail servers.
The receiving server compares the sending server's IP address against the authorized servers listed in the SPF record.
Based on the SPF check result, the server decides whether to accept, flag, or reject the email according to your SPF policy.
Critical for email deliverability and security
SPF records prevent attackers from sending emails that appear to come from your domain. This protects your brand reputation and prevents phishing attacks targeting your customers.
Email providers like Gmail, Outlook, and Yahoo give preference to emails from domains with proper SPF authentication, significantly improving inbox placement rates.
Properly configured email authentication builds trust with email providers and recipients, establishing your domain as a legitimate sender and improving overall reputation.
Many industries and email service providers now require SPF authentication as a baseline security standard for email communications.
If the SPF checker flags a problem, it's usually one of these. Rebuild a clean record with the SPF record generator.
Each include, a, mx, ptr, exists and redirect costs a DNS lookup, and nested includes count too. Past 10, SPF returns a permerror. Fix: remove includes for services you no longer use, and replace static senders with ip4 or ip6 ranges.
A domain can publish only one TXT record that starts with v=spf1. Two records cause a permerror, even if each is valid on its own. Fix: merge every include and IP range into a single record and delete the extra one.
+all authorizes every server on the internet to send as you, and ?all tells receivers to stay neutral. Both make SPF useless. Fix: end your record with ~all (soft fail) while testing, then move to -all (hard fail) once every sender is listed.
If your ESP, CRM or helpdesk sends mail as your domain but isn't in your record, its emails fail SPF. Fix: add the include your provider documents, such as include:_spf.google.com for Google Workspace or include:sendgrid.net for SendGrid.
A permerror means the record is broken (syntax, duplicates or too many lookups), so receivers can't evaluate it. A softfail means the sending IP isn't authorized and you used ~all. Fix: correct the syntax for permerror, and add the missing sender for softfail.
Three records, one job: proving your email is really from you
Lists the servers allowed to send email for your domain. Receivers check the sending IP against it.
Signs each message with a private key so receivers can verify it wasn't changed in transit. Test yours with theDKIM checker.
Tells receivers what to do when SPF or DKIM fails, and reports who sends as your domain. Run aDMARC checknext.
Passing all three proves who you are, but mailbox providers also judge your sending history. A new or recovering domain still needs anemail warmup toolto build that reputation.
Learn more about SPF and email authentication
Complete guide to implementing SPF, DKIM, and DMARC for optimal email security.
Learn why Gmail requires domain authentication and how to set it up properly.
Comprehensive guide to preventing your emails from being marked as spam.
Enhance your email security and deliverability
Check if your domain or IP is on any email blacklists that could affect deliverability.
Verify your domain's DKIM signature configuration and ensure email integrity with cryptographic authentication.
Validate your DMARC policy and check how it aligns with your SPF and DKIM records.
Complete suite of free email tools
Everything you need to know about SPF authentication
Need help with email authentication and deliverability? Mailwarm helps you build sender reputation and ensure your emails reach the inbox. Want the full picture? Run a free email deliverability test.
