Send a transactional e-mail

Sends from a transactional template (template) or from HTML you supply (html). The e-mail is logged, followed (opens and clicks when the template asks for it) and counted against the allowance: each recipient counts, copies included. Without to, the template’s default recipients are used; addresses on the suppression list are left out.

At most 50 recipients per e-mail, to, cc and bcc together (too_many_recipients). mailer names one of the team’s providers or one the platform offers, never another team’s.

The call is answered as soon as the e-mail is logged, and the e-mail leaves from a queue: the answer is usually 202 with status: pending. Follow it with the transactional.* webhooks, or read it again with GET /v1/transactional-mails/{mail} until status is sent or failed. When the provider fails, Lekalao tries again after 5 s, 30 s, 2 min, 10 min and 30 min, and gives up after the sixth failure or six hours after the call (provider_error). An e-mail still pending after 7 hours is declared failed with failure_code: lost.

A refusal is an error with the logged e-mail under data: 422 recipients_suppressed (every address is suppressed), 429 monthly_quota_exceeded (the allowance is used up), 502 only when the provider or the queue failed.

With a test key, nothing leaves: see Test keys.

POST

transactional-mails

send

Send a transactional e-mail

curl --request POST \
  --url https://api.lekalao.com/v1/transactional-mails/send \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "template": "order-confirmation",
  "to": [
    "ada@example.com"
  ],
  "locale": "en",
  "variables": {
    "customer": {
      "name": "Ada"
    },
    "order": {
      "number": "2026-00481",
      "total": "12,500 FCFA",
      "items": [
        "Wholemeal bread",
        "Croissant x4"
      ]
    }
  }
}
'

const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    template: 'order-confirmation',
    to: ['ada@example.com'],
    locale: 'en',
    variables: {
      customer: {name: 'Ada'},
      order: {
        number: '2026-00481',
        total: '12,500 FCFA',
        items: ['Wholemeal bread', 'Croissant x4']
      }
    }
  })
};

fetch('https://api.lekalao.com/v1/transactional-mails/send', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.lekalao.com/v1/transactional-mails/send",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'template' => 'order-confirmation',
    'to' => [
        'ada@example.com'
    ],
    'locale' => 'en',
    'variables' => [
        'customer' => [
                'name' => 'Ada'
        ],
        'order' => [
                'number' => '2026-00481',
                'total' => '12,500 FCFA',
                'items' => [
                                'Wholemeal bread',
                                'Croissant x4'
                ]
        ]
    ]
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

import requests

url = "https://api.lekalao.com/v1/transactional-mails/send"

payload = {
    "template": "order-confirmation",
    "to": ["ada@example.com"],
    "locale": "en",
    "variables": {
        "customer": { "name": "Ada" },
        "order": {
            "number": "2026-00481",
            "total": "12,500 FCFA",
            "items": ["Wholemeal bread", "Croissant x4"]
        }
    }
}
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

{
  "data": {
    "id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
    "template": "<string>",
    "subject": "<string>",
    "from": "jsmith@example.com",
    "to": [
      "jsmith@example.com"
    ],
    "cc": [
      "jsmith@example.com"
    ],
    "bcc": [
      "jsmith@example.com"
    ],
    "status": "pending",
    "sandbox": true,
    "failure_reason": "<string>",
    "failure_code": "recipients_suppressed",
    "opens": 123,
    "clicks": 123,
    "sent_at": "2023-11-07T05:31:56Z",
    "delivered_at": "2023-11-07T05:31:56Z",
    "bounced_at": "2023-11-07T05:31:56Z",
    "complained_at": "2023-11-07T05:31:56Z",
    "created_at": "2023-11-07T05:31:56Z"
  }
}

{
  "data": {
    "id": "e3b0c442-98fc-4c14-9a1e-2f6b7d8a9c10",
    "template": "order-confirmation",
    "subject": "Order 2026-00481 confirmed",
    "from": "hello@mybakery.example",
    "to": [
      "ada@example.com"
    ],
    "cc": [],
    "bcc": [],
    "status": "pending",
    "failure_reason": null,
    "opens": 0,
    "clicks": 0,
    "sent_at": null,
    "created_at": "2026-09-17T10:14:02+00:00"
  }
}

{
  "message": "The idempotency key is too long.",
  "code": "idempotency_key_too_long",
  "doc_url": "https://docs.lekalao.com/errors#idempotency_key_too_long"
}

{
  "message": "Unauthenticated.",
  "code": "unauthenticated",
  "doc_url": "https://docs.lekalao.com/errors#unauthenticated"
}

{
  "message": "This team is suspended. Contact support.",
  "code": "team_suspended",
  "doc_url": "https://docs.lekalao.com/errors#team_suspended"
}

{
  "message": "A request with this idempotency key is already running.",
  "code": "idempotency_key_in_use",
  "doc_url": "https://docs.lekalao.com/errors#idempotency_key_in_use"
}

{
  "message": "Not sent: ada@example.com is on the suppression list.",
  "code": "recipients_suppressed",
  "doc_url": "https://docs.lekalao.com/errors#recipients_suppressed"
}

{
  "message": "<string>",
  "code": "recipients_suppressed",
  "doc_url": "<string>",
  "data": {
    "id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
    "template": "<string>",
    "subject": "<string>",
    "from": "jsmith@example.com",
    "to": [
      "jsmith@example.com"
    ],
    "cc": [
      "jsmith@example.com"
    ],
    "bcc": [
      "jsmith@example.com"
    ],
    "status": "pending",
    "sandbox": true,
    "failure_reason": "<string>",
    "failure_code": "recipients_suppressed",
    "opens": 123,
    "clicks": 123,
    "sent_at": "2023-11-07T05:31:56Z",
    "delivered_at": "2023-11-07T05:31:56Z",
    "bounced_at": "2023-11-07T05:31:56Z",
    "complained_at": "2023-11-07T05:31:56Z",
    "created_at": "2023-11-07T05:31:56Z"
  }
}

{
  "message": "<string>",
  "code": "recipients_suppressed",
  "doc_url": "<string>",
  "data": {
    "id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
    "template": "<string>",
    "subject": "<string>",
    "from": "jsmith@example.com",
    "to": [
      "jsmith@example.com"
    ],
    "cc": [
      "jsmith@example.com"
    ],
    "bcc": [
      "jsmith@example.com"
    ],
    "status": "pending",
    "sandbox": true,
    "failure_reason": "<string>",
    "failure_code": "recipients_suppressed",
    "opens": 123,
    "clicks": 123,
    "sent_at": "2023-11-07T05:31:56Z",
    "delivered_at": "2023-11-07T05:31:56Z",
    "bounced_at": "2023-11-07T05:31:56Z",
    "complained_at": "2023-11-07T05:31:56Z",
    "created_at": "2023-11-07T05:31:56Z"
  }
}

Authorizations

Authorization

string

header

required

An API token. The "read" ability: GET routes only. "read + write": every route.

Headers

Idempotency-Key

string

Replay a write safely: the same key gives back the first answer for 24 hours (header Idempotent-Replay: true). Read on POST, PUT and PATCH; DELETE ignores it. 255 characters at most.

Maximum string length: 255

Body

application/json

template

string | null

The name of one of the team's transactional templates.

html

string | null

The HTML body, when no template is given.

subject

string | null

Replaces the template's subject.

string<email>[]

50 addresses at most, cc and bcc included.

Maximum array length: 50

string<email>[]

Maximum array length: 50

bcc

string<email>[]

Maximum array length: 50

variables

object

They fill the template: {{ order.number }}, {% for %} loops…

locale

string | null

Which language version of the template to send (fr, pt-BR…). Without a value, the base version.

from_email

string<email> | null

from_name

string | null

reply_to

string<email> | null

mailer

string | null

The name of one of the team's providers, or of one the platform offers, to force that one. Any other name is refused.

attachments

object[]

Maximum array length: 10

Show child attributes

Response

The e-mail had already been handed to the provider when the answer left (status: sent).

data

object

Show child attributes

Send a transactional e-mail

curl --request POST \
  --url https://api.lekalao.com/v1/transactional-mails/send \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "template": "order-confirmation",
  "to": [
    "ada@example.com"
  ],
  "locale": "en",
  "variables": {
    "customer": {
      "name": "Ada"
    },
    "order": {
      "number": "2026-00481",
      "total": "12,500 FCFA",
      "items": [
        "Wholemeal bread",
        "Croissant x4"
      ]
    }
  }
}
'

const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    template: 'order-confirmation',
    to: ['ada@example.com'],
    locale: 'en',
    variables: {
      customer: {name: 'Ada'},
      order: {
        number: '2026-00481',
        total: '12,500 FCFA',
        items: ['Wholemeal bread', 'Croissant x4']
      }
    }
  })
};

fetch('https://api.lekalao.com/v1/transactional-mails/send', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.lekalao.com/v1/transactional-mails/send",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'template' => 'order-confirmation',
    'to' => [
        'ada@example.com'
    ],
    'locale' => 'en',
    'variables' => [
        'customer' => [
                'name' => 'Ada'
        ],
        'order' => [
                'number' => '2026-00481',
                'total' => '12,500 FCFA',
                'items' => [
                                'Wholemeal bread',
                                'Croissant x4'
                ]
        ]
    ]
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

import requests

url = "https://api.lekalao.com/v1/transactional-mails/send"

payload = {
    "template": "order-confirmation",
    "to": ["ada@example.com"],
    "locale": "en",
    "variables": {
        "customer": { "name": "Ada" },
        "order": {
            "number": "2026-00481",
            "total": "12,500 FCFA",
            "items": ["Wholemeal bread", "Croissant x4"]
        }
    }
}
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

{
  "data": {
    "id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
    "template": "<string>",
    "subject": "<string>",
    "from": "jsmith@example.com",
    "to": [
      "jsmith@example.com"
    ],
    "cc": [
      "jsmith@example.com"
    ],
    "bcc": [
      "jsmith@example.com"
    ],
    "status": "pending",
    "sandbox": true,
    "failure_reason": "<string>",
    "failure_code": "recipients_suppressed",
    "opens": 123,
    "clicks": 123,
    "sent_at": "2023-11-07T05:31:56Z",
    "delivered_at": "2023-11-07T05:31:56Z",
    "bounced_at": "2023-11-07T05:31:56Z",
    "complained_at": "2023-11-07T05:31:56Z",
    "created_at": "2023-11-07T05:31:56Z"
  }
}

{
  "data": {
    "id": "e3b0c442-98fc-4c14-9a1e-2f6b7d8a9c10",
    "template": "order-confirmation",
    "subject": "Order 2026-00481 confirmed",
    "from": "hello@mybakery.example",
    "to": [
      "ada@example.com"
    ],
    "cc": [],
    "bcc": [],
    "status": "pending",
    "failure_reason": null,
    "opens": 0,
    "clicks": 0,
    "sent_at": null,
    "created_at": "2026-09-17T10:14:02+00:00"
  }
}

{
  "message": "The idempotency key is too long.",
  "code": "idempotency_key_too_long",
  "doc_url": "https://docs.lekalao.com/errors#idempotency_key_too_long"
}

{
  "message": "Unauthenticated.",
  "code": "unauthenticated",
  "doc_url": "https://docs.lekalao.com/errors#unauthenticated"
}

{
  "message": "This team is suspended. Contact support.",
  "code": "team_suspended",
  "doc_url": "https://docs.lekalao.com/errors#team_suspended"
}

{
  "message": "A request with this idempotency key is already running.",
  "code": "idempotency_key_in_use",
  "doc_url": "https://docs.lekalao.com/errors#idempotency_key_in_use"
}

{
  "message": "Not sent: ada@example.com is on the suppression list.",
  "code": "recipients_suppressed",
  "doc_url": "https://docs.lekalao.com/errors#recipients_suppressed"
}

{
  "message": "<string>",
  "code": "recipients_suppressed",
  "doc_url": "<string>",
  "data": {
    "id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
    "template": "<string>",
    "subject": "<string>",
    "from": "jsmith@example.com",
    "to": [
      "jsmith@example.com"
    ],
    "cc": [
      "jsmith@example.com"
    ],
    "bcc": [
      "jsmith@example.com"
    ],
    "status": "pending",
    "sandbox": true,
    "failure_reason": "<string>",
    "failure_code": "recipients_suppressed",
    "opens": 123,
    "clicks": 123,
    "sent_at": "2023-11-07T05:31:56Z",
    "delivered_at": "2023-11-07T05:31:56Z",
    "bounced_at": "2023-11-07T05:31:56Z",
    "complained_at": "2023-11-07T05:31:56Z",
    "created_at": "2023-11-07T05:31:56Z"
  }
}

{
  "message": "<string>",
  "code": "recipients_suppressed",
  "doc_url": "<string>",
  "data": {
    "id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
    "template": "<string>",
    "subject": "<string>",
    "from": "jsmith@example.com",
    "to": [
      "jsmith@example.com"
    ],
    "cc": [
      "jsmith@example.com"
    ],
    "bcc": [
      "jsmith@example.com"
    ],
    "status": "pending",
    "sandbox": true,
    "failure_reason": "<string>",
    "failure_code": "recipients_suppressed",
    "opens": 123,
    "clicks": 123,
    "sent_at": "2023-11-07T05:31:56Z",
    "delivered_at": "2023-11-07T05:31:56Z",
    "bounced_at": "2023-11-07T05:31:56Z",
    "complained_at": "2023-11-07T05:31:56Z",
    "created_at": "2023-11-07T05:31:56Z"
  }
}

Overview

Lists

Subscribers

Tags

Segments

Imports

Templates

Campaigns

Automations

Transactional e-mails

Revenue

Contact fields

Events

Webhooks

Platform

Send a transactional e-mail

Authorizations

Headers

Body

Response