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Email domain checker: SPF, DKIM, DMARC, MX

Enter a domain (for example yourcompany.com) or an email address. The tool reads its MX, SPF, DKIM and DMARC records, tells you what passes and what needs fixing, and suggests the record to add.

DKIM selector (optional)

If your provider gave you a specific selector name (for example s2024), enter it here for an exact check.

Only the domain name is sent, to look up public DNS (via Cloudflare 1.1.1.1). TBN Grow does not store domains or results.

Why check SPF, DKIM and DMARC?

Gmail, Outlook and Yahoo decide between inbox and spam partly by whether the sending domain proves who it is. Since February 2024, Gmail and Yahoo require bulk senders to have SPF, DKIM and DMARC. Missing any of them makes your email more likely to land in spam or be rejected, and makes it easier for scammers to spoof your domain.

The four records checked

  • MX: the servers that receive mail for the domain. Without MX, replies cannot reach you.
  • SPF: a TXT record starting with v=spf1 that lists the servers and services allowed to send as the domain. A domain has one SPF record and at most 10 DNS lookups.
  • DKIM: a digital signature on every message. The public key lives at <selector>._domainkey.<domain>; each sending service has its own selector.
  • DMARC: a TXT record at _dmarc.<domain> telling mailboxes what to do with mail that fails SPF/DKIM: none (monitor), quarantine (spam folder) or reject.

Reading the results

  • Pass: set up correctly.
  • Improve: email still works, but fixing it raises inbox placement.
  • Error: an important setting is missing or wrong; fix it first.
  • The overall score (0–100) is a quick guide; what matters is clearing every "Error".

How to add a TXT record

1. Sign in where your domain’s DNS is managed (Cloudflare, GoDaddy, Namecheap, your registrar…).

2. Open the domain and go to DNS / Manage records.

3. Click Add record and choose type TXT.

4. Name/Host: enter exactly as suggested (@ is the root domain; _dmarc for DMARC).

5. Value: paste the suggested content, without quotes if the panel adds them itself.

6. Save, wait 5–30 minutes (sometimes a few hours), then press Check here again.

Frequently asked questions

I use a personal @gmail.com address. Do I need this?

No. SPF, DKIM and DMARC can only be set for a domain you own. For email marketing, use an address on your own domain (for example hello@yourcompany.com) and set up all three records.

I already have SPF. How do I add a new sending service?

Don’t create a second SPF record. Add the new service’s include to your existing record, before ~all. Example: v=spf1 include:_spf.google.com include:newservice.com ~all.

The tool says DKIM was not found, but I turned it on.

DKIM lives at a "selector" named by your provider, and there is no way to list all selectors. The tool tries common names; if your provider uses a custom one, find it in your email admin and enter it in the "DKIM selector" box.

Should DMARC be p=none, quarantine or reject?

Start with p=none plus rua to receive reports for 2–4 weeks. When every real source of your mail passes SPF/DKIM, move to p=quarantine, then p=reject. Moving too early can block your own legitimate mail.

How long until changes take effect?

Usually 5–30 minutes, up to 24–48 hours depending on your DNS host. The tool always reads the latest public DNS data.

Does the tool store the domain I enter?

No. The check runs in your browser; only the domain name is sent to Cloudflare’s public DNS lookup service (1.1.1.1), with Google DNS as a fallback. TBN Grow stores neither the domain nor the results.