Read messages from an IMAP mailbox
Read messages from an IMAP mailbox using caller-supplied server credentials, with an optional filterflat)
Request
- x-api-key: <your-api-key>
- Content-Type: application/json
Response
{
"messages": [
{}
],
"status": "success",
"tokensDeducted": 2
}What it does
Read messages from an IMAP mailbox using caller-supplied server credentials, with an optional filterflat)
Request
Body
| Field | Type | Required | Description |
|---|---|---|---|
filter | object | no | |
↳ attachmentExtensions | array<string> | no | |
↳ before | string | no | |
↳ from | string | no | |
↳ hasAttachment | boolean | no | |
↳ since | string | no | |
↳ subject | string | no | |
↳ unseenOnly | boolean | no | |
limit | integer | no | |
mailbox | string | no | |
markAsRead | boolean | no | |
server | object | yes | |
↳ host | string | yes | |
↳ password | string | yes | |
↳ port | integer | yes | |
↳ secure | boolean | yes | |
↳ username | string | yes |
Example request
{
"filter": {},
"limit": 20,
"mailbox": "INBOX",
"markAsRead": false,
"server": {
"host": "example.com",
"password": "correct-horse-battery-staple",
"port": 5,
"secure": true,
"username": "ada"
}
}Response
| Field | Type | Description |
|---|---|---|
messages | array<object> | |
status | string | |
tokensDeducted | integer |
Example response
{
"messages": [
{}
],
"status": "success",
"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/email/read' \
-H 'x-api-key: <your-api-key>' \
-H 'Content-Type: application/json' \
-d '{"filter": {}, "limit": 20, "mailbox": "INBOX", "markAsRead": false, "server": {"host": "example.com", "password": "correct-horse-battery-staple", "port": 5, "secure": true, "username": "ada"}}'const res = await fetch('https://app.castomapi.com/v1/email/read', {
method: 'POST',
headers: { 'x-api-key': '<your-api-key>', 'Content-Type': 'application/json' },
body: JSON.stringify({"filter": {}, "limit": 20, "mailbox": "INBOX", "markAsRead": false, "server": {"host": "example.com", "password": "correct-horse-battery-staple", "port": 5, "secure": true, "username": "ada"}})
});
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/email/read', {
method: 'POST',
headers: { 'x-api-key': '<your-api-key>', 'Content-Type': 'application/json' },
body: JSON.stringify({"filter": {}, "limit": 20, "mailbox": "INBOX", "markAsRead": false, "server": {"host": "example.com", "password": "correct-horse-battery-staple", "port": 5, "secure": true, "username": "ada"}})
});
const data = await res.json();
console.log(data);import requests
res = requests.post(
'https://app.castomapi.com/v1/email/read',
headers={'x-api-key': '<your-api-key>'},
json={"filter": {}, "limit": 20, "mailbox": "INBOX", "markAsRead": False, "server": {"host": "example.com", "password": "correct-horse-battery-staple", "port": 5, "secure": True, "username": "ada"}},
timeout=30,
)
print(res.json())<?php
$ch = curl_init('https://app.castomapi.com/v1/email/read');
curl_setopt_array($ch, [
CURLOPT_CUSTOMREQUEST => 'POST',
CURLOPT_RETURNTRANSFER => true,
CURLOPT_HTTPHEADER => ['x-api-key: <your-api-key>', 'Content-Type: application/json'],
CURLOPT_POSTFIELDS => json_encode(['filter' => [], 'limit' => 20, 'mailbox' => 'INBOX', 'markAsRead' => false, 'server' => ['host' => 'example.com', 'password' => 'correct-horse-battery-staple', 'port' => 5, 'secure' => true, 'username' => 'ada']]),
]);
$data = json_decode(curl_exec($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 Read messages from an IMAP mailbox 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