Free Email Security Test
Validates SPF, DKIM, and DMARC DNS records to stop attackers from spoofing your domain. Runs in seconds against any domain, no signup, with step-by-step fixes.
- SPF record check
- DKIM validation
- DMARC policy check

What you get for free
18 core security checks via this tool, passive scans, step-by-step remediation, security score on every result.
What Essential adds at $39/mo
+17 advanced checks, continuous monitoring, daily security score history, email alerts, GitHub SAST, board-ready PDFs, SOC 2 / ISO 27001 / PCI reports.
How to fix common issues
- Keep SPF under 10 DNS lookups (flatten or consolidate providers)
- Rotate DKIM keys and use at least 2048‑bit where supported
- Move DMARC from p=none to quarantine/reject once aligned and monitored
Examples (good vs bad)
Good SPF: v=spf1 include:spf.provider.com -all
Bad SPF: v=spf1 a mx ip4:0.0.0.0/0 ~all
What this test checks
- SPF: record presence, syntax, includes, and DNS lookup count
- DKIM: selector discovery, key length hints, alignment notes
- DMARC: policy (none/quarantine/reject), alignment, rua/ruf reporting
Across 908 recent SPF/DKIM/DMARC checks, 33.0% are missing at least one of the three. Email auth is the lowest-effort high-impact email security control most teams skip.
What is email domain security?
Email authentication relies on DNS records that tell receiving servers which hosts can send on your behalf (SPF), how to verify message integrity (DKIM), and what to do with failures (DMARC). A solid setup dramatically reduces spoofing and improves deliverability.
Implementation examples
Once you've identified the gap, applying the fix is straightforward. Here are the three configurations developers reach for most often.
BIND zone file
example.com. IN TXT "v=spf1 include:_spf.google.com -all"
selector1._domainkey IN TXT "v=DKIM1; k=rsa; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCg..."
_dmarc IN TXT "v=DMARC1; p=reject; rua=mailto:dmarc@example.com; adkim=s; aspf=s"Cloudflare (API)
# SPF
{ "type": "TXT", "name": "example.com",
"content": "v=spf1 include:_spf.google.com -all", "ttl": 3600 }
# DKIM
{ "type": "TXT", "name": "selector1._domainkey.example.com",
"content": "v=DKIM1; k=rsa; p=MIIBIjANBgkqhkiG9w0BAQE...", "ttl": 3600 }
# DMARC
{ "type": "TXT", "name": "_dmarc.example.com",
"content": "v=DMARC1; p=reject; rua=mailto:dmarc@example.com; adkim=s; aspf=s",
"ttl": 3600 }AWS Route 53 (change-resource-record-sets)
{
"Changes": [
{
"Action": "UPSERT",
"ResourceRecordSet": {
"Name": "example.com.",
"Type": "TXT",
"TTL": 3600,
"ResourceRecords": [
{ "Value": "\"v=spf1 include:amazonses.com -all\"" }
]
}
},
{
"Action": "UPSERT",
"ResourceRecordSet": {
"Name": "_dmarc.example.com.",
"Type": "TXT",
"TTL": 3600,
"ResourceRecords": [
{ "Value": "\"v=DMARC1; p=reject; rua=mailto:dmarc@example.com; adkim=s; aspf=s\"" }
]
}
}
]
}Tool-specific questions
What does this email security test check?
Should DMARC be p=none?
How many DKIM selectors?
What breaks SPF?
Built for the engineers who already have enough to fix.
Real-time results
Comprehensive checks
Step-by-step fixes
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Go deeper on the same topic.
Email Security
Email Authentication Spf Dkim Dmarc
Spf Dkim Dmarc Guide
Frequently asked.
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Anything else? Email contact@barrion.io.
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