Free tool
Email Security Checker
Check your domain's SPF, DKIM and DMARC in seconds. See whether criminals can spoof your email and why your messages might be landing in junk, with plain-English fixes.
We only look up public DNS records. Nothing is sent to your mailbox and we don't store the result.
What we check
- SPF
- Whether your domain lists the servers allowed to send its email, ends with a safe rule, and stays within the 10 DNS lookups receivers allow.
- DKIM
- Whether signing keys are published for Microsoft 365, Google Workspace and other common providers, so receivers can verify your emails haven't been tampered with.
- DMARC
- Whether you have a policy that blocks spoofed email (quarantine or reject) and a reporting address so you can see who is sending as you.
- Mail servers
- Who handles your email, so the advice matches your provider.
Related guides
Email security FAQs
SPF lists which servers are allowed to send email for your domain. DKIM adds a digital signature so receivers can tell the email wasn't altered. DMARC tells receivers what to do with email that fails those checks, and sends you reports about who is sending as your domain.
Major providers like Microsoft and Google now expect SPF, DKIM and DMARC together. A missing DKIM key or DMARC record, too many SPF lookups, or a marketing tool that isn't included in SPF are common reasons legitimate email lands in junk.
Only once your DMARC reports show that every legitimate service sending as your domain passes SPF or DKIM. Start at p=none, fix anything failing, move to p=quarantine, then p=reject. Jumping straight to reject can block your own invoices or newsletters.
DKIM keys live under a 'selector' name chosen by your email provider. We check the selectors used by Microsoft 365, Google Workspace and other common services. If your provider uses a custom selector, DKIM may be working even if we can't see it.
No. It only reads public DNS records that anyone on the internet can see. Nothing is sent to your mailbox and we don't store the domains you check.
Want it fixed properly?
We set up SPF, DKIM and DMARC for small businesses without breaking the tools that send email for you, then monitor the reports so nothing slips.