Introduction

This is the official documentation for MailRush.io API v2. The API is RESTful and uses JSON over HTTPS.

POST /email — Send Email

Send a single email using an SMTP account that belongs to your organization. Attachments are not supported in v2.

Request example (cURL)

curl -X POST https://app2.mailrush.io/api/v2/email   -H "Content-Type: application/json"   -H "x-api-key: YOUR_API_KEY"   -d '{
    "fromEmail": "notificaciones@yourdomain.com",
    "recipientEmail": "alice@example.com",
    "subject": "Welcome!",
    "html": "
Hello
Your account is ready.
"
  }'

Successful response

{ "success": true, "messageId": "" }

POST /contacts — Create Contact

Create a contact inside your organization and assign it to a tag. If the tag does not exist, it is created. Duplicate emails are rejected.

Request example (cURL)

curl -X POST https://app2.mailrush.io/api/v2/contacts   -H "Content-Type: application/json"   -H "x-api-key: YOUR_API_KEY"   -d '{
    "email": "maria.perez@example.com",
    "first_name": "Maria",
    "last_name": "Perez",
    "company": "Example Inc.",
    "tag": "customers"
  }'

Successful response (201)

{
  "success": true,
  "contact_id": 12345,
  "public_id": "4f9d2f0e3b1c4e21b6c2f8d1",
  "tag": "customers"
}

POST /contacts/unsubscribe — Unsubscribe Contact

Unsubscribe a contact (opt-out) by email within your organization. The operation is idempotent.

Request example (cURL)

curl -X POST https://app2.mailrush.io/api/v2/contacts/unsubscribe   -H "Content-Type: application/json"   -H "x-api-key: YOUR_API_KEY"   -d '{ "email": "jon@example.com" }'

Successful responses

{ "success": true, "message": "Unsubscribed successfully" }

{ "success": true, "message": "Already unsubscribed" }

Authentication

MailRush.io uses API Key authentication. Include your private key in the x-api-key header on every request. All endpoints require HTTPS/TLS.

x-api-key: YOUR_API_KEY
Content-Type: application/json

Status Codes