Parse EML and Outlook MSG email files into structured headers
Parse EML and Outlook MSG email files into structured headers, security auth status (SPF/DKIM/DMARC), clean Markdown body, and decoded attachments
Request
- x-api-key: <your-api-key>
- Content-Type: application/json
This operation is read-only. Change the path values above and send.
Response
{
"attachments": [
{
"base64": "SGVsbG8gZnJvbSBjYXN0b21BUEk=",
"contentId": "con_893378",
"contentType": "application/pdf",
"filename": "report.pdf",
"size": 1024
}
],
"bcc": [],
"cc": [],
"content": {
"hasAttachments": true,
"html": "<h1>Hello</h1><p>From castomAPI.</p>",
"markdown": "# Hello\n\nFrom castomAPI.",
"text": "Hello from castomAPI."
},
"date": "2026-09-08",
"formatDetected": "EML",
"from": {},
"messageId": "mes_434410",
"security": {
"dkim": "pass",
"dmarc": "pass",
"spf": "pass"
},
"sourceType": "raw_content",
"status": "success",
"subject": "Your September invoice",
"to": [
{}
],
"tokensDeducted": 2
}What it does
Parse EML and Outlook MSG email files into structured headers, security auth status (SPF/DKIM/DMARC), clean Markdown body, and decoded attachments
Request
Response
| Field | Type | Description |
|---|---|---|
attachments | array<object> | |
↳ base64 | string | |
↳ contentId | string | |
↳ contentType | string | |
↳ filename | string | |
↳ size | integer | |
bcc | array<object> | |
cc | array<object> | |
content | object | |
↳ hasAttachments | boolean | |
↳ html | string | |
↳ markdown | string | |
↳ text | string | |
date | string | |
formatDetected | enum | One of: EML, MSG. |
from | object | |
messageId | string | |
security | object | |
↳ dkim | enum | One of: pass, fail, none. |
↳ dmarc | enum | One of: pass, fail, none. |
↳ spf | enum | One of: pass, fail, none. |
sourceType | enum | One of: raw_content, url, file_upload. |
status | string | |
subject | string | |
to | array<object> | |
tokensDeducted | integer |
Example response
{
"attachments": [
{
"base64": "SGVsbG8gZnJvbSBjYXN0b21BUEk=",
"contentId": "con_893378",
"contentType": "application/pdf",
"filename": "report.pdf",
"size": 1024
}
],
"bcc": [],
"cc": [],
"content": {
"hasAttachments": true,
"html": "<h1>Hello</h1><p>From castomAPI.</p>",
"markdown": "# Hello\n\nFrom castomAPI.",
"text": "Hello from castomAPI."
},
"date": "2026-09-08",
"formatDetected": "EML",
"from": {},
"messageId": "mes_434410",
"security": {
"dkim": "pass",
"dmarc": "pass",
"spf": "pass"
},
"sourceType": "raw_content",
"status": "success",
"subject": "Your September invoice",
"to": [
{}
],
"tokensDeducted": 2
}Errors
Every error answers with the same envelope: an HTTP status, a machine code and a sentence.
400 | The body or a parameter failed validation. The details array names the field. |
401 | No key, a revoked key or a wrong header. Send x-api-key. |
402 | The wallet cannot cover this call. Top up or wait for the monthly grant. |
404 | The resource does not exist, or it is not yours. Both answer identically and cost nothing. |
429 | Over the per-minute quota of your tier. Back off and retry. |
5xx | Upstream refused or timed out. The call is not billed. |
Code
curl -X POST 'https://app.castomapi.com/v1/parse/email' \ -H 'x-api-key: <your-api-key>'
const res = await fetch('https://app.castomapi.com/v1/parse/email', {
method: 'POST',
headers: { 'x-api-key': '<your-api-key>' }
});
const data = await res.json();
console.log(data);import { request } from 'node:https';
// Node 18+ has fetch built in
const res = await fetch('https://app.castomapi.com/v1/parse/email', {
method: 'POST',
headers: { 'x-api-key': '<your-api-key>' }
});
const data = await res.json();
console.log(data);import requests
res = requests.post(
'https://app.castomapi.com/v1/parse/email',
headers={'x-api-key': '<your-api-key>'},
timeout=30,
)
print(res.json())<?php
$ch = curl_init('https://app.castomapi.com/v1/parse/email');
curl_setopt_array($ch, [
CURLOPT_CUSTOMREQUEST => 'POST',
CURLOPT_RETURNTRANSFER => true,
CURLOPT_HTTPHEADER => ['x-api-key: <your-api-key>', 'Content-Type: application/json'],
]);
$data = json_decode(curl_exec($ch), true);
print_r($data);Cost and limits
This operation costs 2 tokens. A call that fails is never billed. Every account gets 1000 free tokens a month; paid balances never expire.
Rate limits per minute
| No key | 10 |
| Free | 60 |
| Pro | 300 |
| Enterprise | 1200 |
Questions
What does Parse EML and Outlook MSG email files into structured headers cost?
2 tokens per successful call, debited from your wallet after the response. Failed calls are free. Every account receives 1000 free tokens a month.
How do I authenticate?
Send your key in the x-api-key header. One key covers every metered endpoint; there is nothing to enable per endpoint.
Can I send an Authorization: Bearer token instead?
Not for a metered endpoint — those take the x-api-key header and nothing else. Bearer tokens belong to the account side: the dashboard and account APIs accept a JWT session, and castomapi-auth issues those through a standard OAuth2 handshake, with authorization code, client credentials and refresh grants. The auth service page covers it.
What are the limits?
10 requests a minute per IP with no key at all, 60 a minute on the free tier, 300 on Pro, 1200 on Enterprise. Above the no-key tier the quota is per account, across every endpoint.
OpenAPI: https://app.castomapi.com/docs/json