Free DMARC Compliance Checker

The domain checker runs a full email authentication audit on any domain. No account or signup required.

URL: celeric.app/check

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How to use it

1. Go to celeric.app/check

2. Enter a domain name (e.g., yourdomain.com) — do not include https:// or www

3. Click Check or press Enter

4. Results appear in a few seconds

You can also go directly to celeric.app/check/yourdomain.com for a shareable link to any domain's report.

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Understanding your score

Your compliance score is a single number from 0 to 100 calculated from six checks:

Score colors:

• 80–100 (green) — well-configured, good deliverability
• 50–79 (yellow) — some issues, emails may be filtered as spam
• 0–49 (red) — critical problems, emails likely failing authentication

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Individual check results

Each check shows one of three statuses:

• Pass — the check passed without issues
• Warning — the record exists but has configuration problems
• Fail — the record is missing or fundamentally broken

Click any check card to expand it and see:

• The current DNS records Celeric found
• Step-by-step instructions to fix any issues
• The exact DNS record you need to add (with a copy button)

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What each check means

SPF (Sender Policy Framework)

SPF tells receiving mail servers which IP addresses are allowed to send email for your domain. Without a valid SPF record, your emails are more likely to be rejected or marked as spam.

What Celeric checks:

• SPF TXT record exists at your domain root
• Only one SPF record exists (multiple records break SPF)
• Record doesn't exceed 10 DNS lookups (the RFC 7208 limit)
• Policy ends with -all (hard fail) or ~all (soft fail) — +all is flagged as insecure

DKIM (DomainKeys Identified Mail)

DKIM adds a cryptographic signature to outgoing emails that proves they weren't tampered with in transit. Your email provider (Gmail, Outlook, etc.) adds the signature — you just need the DNS record in place.

What Celeric checks:

• Probes common DKIM selectors (e.g., google, selector1, mail, etc.) to find your key
• Verifies the DKIM public key record is valid and properly formatted

Note: Celeric checks common selectors automatically. If you use a less common selector from a third-party email service, it may not be detected, but that doesn't mean DKIM isn't working.

DMARC (Domain-based Message Authentication)

DMARC tells receiving mail servers what to do with emails that fail SPF or DKIM (nothing, quarantine to spam, or reject). It's also where you configure RUA reporting to receive delivery reports.

What Celeric checks:

• DMARC TXT record exists at _dmarc.yourdomain.com
• Policy is set (p=none, p=quarantine, or p=reject)
• Provides progressive recommendations toward stricter policy

DMARC policies:

• p=none — monitor only, no action taken on failures (weakest)
• p=quarantine — failed emails go to spam
• p=reject — failed emails are rejected outright (strongest)

MX Records

MX records tell other mail servers where to deliver incoming email for your domain. Without them, you can't receive email.

What Celeric checks:

• At least one MX record exists
• Detects your email provider (Google Workspace, Microsoft 365, etc.)

Blacklist

Checks whether your domain's primary mail server IP address is listed on major spam blacklists. Being blacklisted causes most emails to be rejected or filtered.

What Celeric checks:

• Spamhaus ZEN
• SpamCop
• Barracuda
• SORBS
• Backscatterer

DNS

Basic DNS health check for the domain.

What Celeric checks:

• Domain has an A record (resolves to an IP address)
• Forward-confirmed reverse DNS (FCrDNS) — the IP's PTR record matches the sending hostname

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Sharing results

Every check has a permanent shareable URL:

celeric.app/check/yourdomain.com

Send this link to a colleague, client, or your IT team — it shows the full report for that domain.

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Getting a report by email

After running a check, you'll see a "Get Your Full DMARC Report" prompt. Enter your email to receive a copy of the report. No account needed.

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What comes next

The free checker is a one-time snapshot. For continuous monitoring with alerts when something changes, see Domain Monitoring.