flask-mailjet

flask-mailjet

A lightweight, secure, and production-ready Flask extension for sending emails through the Mailjet API, built on top of the official mailjet-rest library.

🚀 Features

• Simple configuration via MAILJET_API_KEY and MAILJET_API_SECRET
• Straightforward email sending (HTML, multiple recipients)
• Built‑in support for file attachments
• Templating helper for rendering email templates
• Works with both eager app initialization and the Flask Factory pattern
• Clean API fully aligned with Mailjet's expectations

📦 Installation

pip install flask-mailjet

🛠️ Configuration

Add the following to your Flask application configuration:

app.config["MAILJET_API_KEY"] = "YOUR_API_KEY"
app.config["MAILJET_API_SECRET"] = "YOUR_API_SECRET"

Variable Description

MAILJET_API_KEY Your Mailjet API Public Key MAILJET_API_SECRET Your Mailjet API Secret Key

🔧 Initialization

Option 1: Eager Initialization

from flask import Flask
from flask_mailjet import Mailjet

app = Flask(__name__)
app.config["MAILJET_API_KEY"] = "YOUR_API_KEY"
app.config["MAILJET_API_SECRET"] = "YOUR_API_SECRET"

mailjet = Mailjet(app)

Option 2: Factory Pattern

from flask_mailjet import Mailjet

mailjet = Mailjet()

def create_app():
    app = Flask(__name__)
    app.config.from_mapping(
        MAILJET_API_KEY="YOUR_API_KEY",
        MAILJET_API_SECRET="YOUR_API_SECRET",
    )

    mailjet.init_app(app)
    return app

✉️ Sending Emails

All mail‑sending methods expect the sender field as:

{"Email": "[e-mail]", "Name": "Sender Name"}

1. send_email --- Basic HTML Email

from_user = {"Email": "[e-mail]", "Name": "App Alerts"}
to_user = ["[e-mail]", "[e-mail]"]

mailjet.send_email(
    sender=from_user,
    recipients=to_user,
    subject="Your Account Is Active",
    html="<h1>Welcome!</h1><p>Your subscription is confirmed.</p>"
)

2. send_email_with_attachment --- Email + File Attachment

import os

pdf_path = os.path.join(app.root_path, "static", "invoice.pdf")
with open(pdf_path, "rb") as f:
    pdf_bytes = f.read()

mailjet.send_email_with_attachment(
    sender={"Email": "[e-mail]"},
    recipients="[e-mail]",
    subject="Q4 Financial Report",
    html="<p>Attached is the report.</p>",
    filename="Q4_Report.pdf",
    file_bytes=pdf_bytes,
    content_type="application/pdf",
)

🎨 Template Rendering (loader.py)

You can render email templates stored in:

flask_mailjet/templates/mailjet/

Example

from flask_mailjet.loader import render_email_template

email_html = render_email_template(
    "welcome.html",
    user_name="Tim",
    link="https://app.example.com"
)

mailjet.send_email(
    sender={"Email": "[e-mail]"},
    recipients="[e-mail]",
    subject="Welcome!",
    html=email_html,
)

📁 Project Structure Example

yourapp/
├── app.py
├── templates/
│   └── mailjet/
│       └── welcome.html
└── extensions/
    └── mailjet.py

🧪 Testing

You can mock Mailjet easily using Python's builtin tools:

from unittest.mock import patch

@patch("flask_mailjet.Mailjet.send_email")
def test_send(mock_send):
    mock_send.return_value = {"Status": "success"}

📜 License

MIT License.

🤝 Contributing

Pull requests are welcome.
Please open an issue first to discuss major changes.

⭐ Support

If this extension helps you, consider starring the repository!