Email Tools
SPF Checker
Check whether a domain has a valid SPF record configured.
Enter a domain to check its SPF record.
JustChecker tracks your email authentication records continuously.
Frequently Asked Questions
SPF ("Sender Policy Framework") publishes which mail servers are authorized to send email on your domain's behalf - receiving mail servers check this list, making it harder for an attacker to send forged email that appears to come from your domain.
SPF alone is only one of several signals receiving mail servers weigh - DKIM and DMARC configuration, sender reputation, and content-based spam filtering all factor in independently; SPF being correct doesn't guarantee delivery on its own.
SPF records have a hard limit of 10 DNS lookups during evaluation - including services like Google Workspace, Mailchimp, or other senders each adds lookups, and exceeding the limit causes receiving servers to treat the entire SPF check as failed.
"-all" (hard fail) tells receiving servers to reject mail from unlisted senders outright; "~all" (soft fail) asks them to flag it as suspicious but not necessarily reject it - "-all" is stricter and generally recommended once you're confident your SPF record is complete.
SPF records don't automatically inherit to subdomains - if you send mail from a subdomain, it typically needs its own explicitly configured SPF record rather than relying on the root domain's.
Yes - modern receiving servers increasingly expect DKIM and a DMARC policy alongside SPF; having only SPF configured is a good start but leaves gaps that DMARC and DKIM specifically close.