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POST
/
api
/
v1
/
emails
Send Email
curl --request POST \
  --url https://api.example.com/api/v1/emails \
  --header 'Content-Type: application/json' \
  --data '
{
  "from": "<string>",
  "to": [
    "<string>"
  ],
  "subject": "<string>",
  "html": "<string>",
  "text": "<string>",
  "templateId": "<string>",
  "variables": {},
  "attachmentIds": [
    "<string>"
  ],
  "cc": [
    "<string>"
  ],
  "bcc": [
    "<string>"
  ],
  "replyTo": "<string>",
  "headers": {},
  "idempotencyKey": "<string>"
}
'
{
  "id": "<string>",
  "status": "<string>",
  "messageId": "<string>",
  "createdAt": "<string>"
}

Documentation Index

Fetch the complete documentation index at: https://docs.mailbreeze.com/llms.txt

Use this file to discover all available pages before exploring further.

Send an email using raw content or a pre-built template.

​
Request Body

​
from
string
required
Sender email address. Must match a verified domain. Supports display name format: "Name" <email@domain.com>
​
to
string | string[]
required
Recipient email address(es). If array, all recipients see each other (single email, not batch).
​
subject
string
Email subject line (max 998 characters, no newlines). Required unless using a template.
​
html
string
HTML content of the email. Required if not using templateId.
​
text
string
Plain text fallback content.
​
templateId
string
Template ID to use instead of raw html/text. Subject comes from template unless overridden.
​
variables
object
Key-value pairs for template variable substitution ({{variable}}).
​
attachmentIds
string[]
IDs of attachments to include (from the attachments upload flow).
​
cc
string | string[]
CC recipients.
​
bcc
string | string[]
BCC recipients.
​
replyTo
string
Reply-to email address.
​
headers
object
Custom email headers to include.
​
idempotencyKey
string
Unique key to prevent duplicate sends. Valid for 24 hours, max 256 characters.

​
Content Options

You must provide content in one of two ways: Option 1: Direct Content 
{
  "from": "hello@yourdomain.com",
  "to": "user@example.com",
  "subject": "Welcome!",
  "html": "<h1>Welcome!</h1>",
  "text": "Welcome!"
}
Option 2: Template 
{
  "from": "hello@yourdomain.com",
  "to": "user@example.com",
  "templateId": "welcome-template",
  "variables": {
    "name": "John",
    "plan": "Pro"
  }
}

​
Examples

import { MailBreeze } from "mailbreeze";

const mailbreeze = new MailBreeze({ apiKey: "sk_live_xxx" });

// Send with direct content
const result = await mailbreeze.emails.send({
  from: "hello@yourdomain.com",
  to: "user@example.com",
  subject: "Welcome!",
  html: "<h1>Welcome to our platform!</h1>",
  text: "Welcome to our platform!",
});

console.log(result.id); // "msg_xxx"

// Send with template
const result = await mailbreeze.emails.send({
  from: "hello@yourdomain.com",
  to: "user@example.com",
  templateId: "welcome-template",
  variables: {
    name: "John",
    plan: "Pro",
  },
});

​
Response

​
id
string
Unique email ID.
​
status
string
Current status: queued, sent, delivered, bounced, or failed.
​
messageId
string
SMTP message ID.
​
createdAt
string
ISO 8601 timestamp when queued.
Success Response
{
  "success": true,
  "data": {
    "messageId": "ea296955-b253-424b-9bf4-761381e8dedc"
  },
  "meta": {
    "timestamp": "2025-12-27T13:36:06.342Z",
    "requestId": "e69b115b-21e5-4051-a0bf-550c39ad7c1a",
    "path": "/api/v1/emails"
  }
}

​
Test Mode Response

When using a test API key (sk_test_*), emails are simulated:
Sandbox Response
{
  "success": true,
  "data": {
    "sandbox": true,
    "messageId": "sandbox_abc123xyz",
    "message": "Email simulated (test mode) - no real email was sent",
    "recipients": ["user@example.com"]
  },
  "meta": {
    "timestamp": "2024-01-15T10:30:00.000Z",
    "requestId": "req_abc123",
    "path": "/api/v1/emails"
  }
}
SDKs automatically extract the data field, so you access result.messageId directly.

​
Errors

CodeDescription
DNS_VERIFICATION_FAILEDDomain DNS records not verified
DOMAIN_VALIDATION_FAILEDDomain not active or verified
FROM_DOMAIN_MISMATCHFrom address domain must match verified domain
TEMPLATE_NOT_FOUNDTemplate ID doesn’t exist
TEMPLATE_RENDER_ERRORTemplate variable substitution failed
ATTACHMENT_NOT_FOUNDAttachment ID doesn’t exist
ATTACHMENT_TOO_LARGEAttachment exceeds 10MB limit
EMAIL_TOO_LARGETotal email exceeds 10MB limit
SPAM_SCORE_TOO_HIGHContent flagged as spam
RECIPIENT_SUPPRESSEDRecipient is on suppression list