Read the authentication headers a receiver added to one message
Read the authentication headers a receiver added to one message. Headers are unfolded first, because a field continues on any line beginning with whitespace. Reports two From headers, where what is displayed and what is evaluated can differ, which is the shape of a spoof rather than a mistake; a lower Authentication-Results, which can have been written before the message arrived; a result from an untrusted server; and a DKIM or SPF domain that does not align with the From domain.
Paid test badge: not yet. The checks above are free: we call the tool without paying and read the payment request it sends back. The Verified badge needs paid calls whose answers match the promised output, and nobody can buy a badge.
Endpoint
POST https://api.zfinia.com/x402/v1/email-header-authentication-audit
| Category | Code and developer |
|---|---|
| Provider host | api.zfinia.com |
| Networks | eip155:8453 |
| Payment schemes | exact |
| Self-reported calls, 30 days | 1 from 1 payers (the provider's figure, not ours) |
Our checks, last 30 days
| Day | Result | HTTP | Asked | Time |
|---|---|---|---|---|
| 2026-10-04 | no answer |
Example input (from the provider)
{
"body": {
"expected_from_domain": "example.test",
"headers": "Received: from relay.vendor.test (relay.vendor.test [198.51.100.7])\n\tby mx.receiver.test with ESMTPS id abc123\n\tfor <ada@receiver.test>; Thu, 2 Oct 2026 12:00:00 +0000\nAuthentication-Results: relay.vendor.test;\n\tspf=softfail smtp.mailfrom=bounces.vendor.test;\n\tdkim=pass header.d=vendor.test;\n\tdmarc=fail\nAuthentication-Results: mx.receiver.test; spf=pass smtp.mailfrom=example.test; dkim=pass header.d=example.test\nFrom: Billing <billing@example.test>\nFrom: Billing <billing@example-test.test>\nSubject: Your invoice\n",
"trusted_authserv_ids": [
"mx.receiver.test"
]
},
"bodyType": "json",
"method": "POST",
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"additionalProperties": false,
"properties": {
"expected_from_domain": {
"maxLength": 253,
"type": "string"
},
"headers": {
"maxLength": 131072,
"type": "string"
},
"trusted_authserv_ids": {
"items": {
"maxLength": 253,
"type": "string"
},
"maxItems": 50,
"minItems": 1,
"type": "array"
}
},
"required": [
"headers"
],
"type": "object"
},
"bodyType": {
"enum": [
"json",
"form-data",
"text"
],
"type": "string"
},
"method": {
"enum": [
"POST"
],
"type": "string"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method",
"bodyType",
"body"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}