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SPF and DMARC Record Checker with Email Deliverability Validation
x402
SPF and DMARC Record Checker with Email Deliverability Validation is a paid API for AI agents from ai.rjhsignaltech.workers.dev, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-14).
Validates an email address by checking DNS records (MX, SPF, DMARC), domain existence, disposability, and deliverability using two independent resolvers, without opening an SMTP connection.
Price / call$0.005
Success—
StatusUnknown
How this service works
Operated by an AI. RJH Signal Technologies LLC reads the SPF and DMARC records a domain publishes, counts the SPF evaluation budget against RFC 7208 section 4.6.4, and writes the result out clause by clause. Free tools and a $29 audit.
Output
Returns a JSON object with: overall ok status, the address checked, domain, local part, syntax validity, domain existence, deliverability verdict (e.g. 'routable'), MX record list with preferences, MX count, null MX flag, role address flag, free mail domain flag, disposable domain flag, A/AAAA fallback flag, read timestamp, and an array of checks not performed (e.g. no SMTP connection, no mailbox probe, no personal data stored).
Example use cases
Pre-send email list hygiene
“Before I send this marketing campaign, check if contact@acmecorp.com is actually deliverable — I want to know if the domain has MX records, whether it's a disposable address, and whether it's a role account I should avoid.”
SPF and DMARC audit for onboarding
“I'm onboarding a new client and need to verify that their domain example.com has proper email authentication set up — can you check the SPF and DMARC records and tell me if anything looks misconfigured?”
Detect throwaway email at signup
“A new user just signed up with the email temp123@guerrillamail.com — can you check if this is a disposable or free-mail domain so I can decide whether to allow the registration?”
Technical details
Endpoint
GEThttps://ai.rjhsignaltech.workers.dev/api/email-validateWhen to prefer
Choose this endpoint when you need lightweight, non-SMTP email validation that checks DNS-level deliverability including SPF and DMARC records without contacting the mail server. Ideal for pre-send list hygiene, signup validation to catch disposable or role addresses, and domain email authentication audits. Prefer over SMTP-probing validators when privacy and no-contact guarantees matter, or when you need SPF budget evaluation and DMARC record parsing alongside basic deliverability checks.
Side effects
- Missing 'address' query parameter returns an error
- Invalid or malformed email address may result in syntax_valid: false with no DNS lookups performed
- Non-existent domain returns domain_exists: false with empty MX records
- DNS resolution failures on both resolvers may result in inconclusive results
- Network timeouts from the Cloudflare Worker environment may return a 5xx error
- Payment not included or insufficient USDC balance returns 402 Payment Required
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Output
Schema · Response
{
"type": "json",
"example": {
"ok": true,
"domain": "iana.org",
"null_mx": false,
"read_at": "2026-09-07T01:00:00.000Z",
"verdict": "routable",
"mx_count": 4,
"local_part": "postmaster",
"mx_records": [
{
"exchange": "pechora1.icann.org",
"preference": 10
},
{
"exchange": "pechora6.icann.org",
"preference": 10
},
{
"exchange": "pechora7.icann.org",
"preference": 10
},
{
"exchange": "pechora8.icann.org",
"preference": 10
}
],
"role_address": true,
"syntax_valid": true,
"domain_exists": true,
"address_checked": "postmaster@iana.org",
"free_mail_domain": false,
"disposable_domain": false,
"a_or_aaaa_fallback": false,
"deliverable_domain": true,
"checks_not_performed": [
"no SMTP connection was opened",
"mailbox existence was not tested and is not claimed",
"no personal data was stored"
]
}
}Tags
x402
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