Step-by-Step Guide for Sending Emails via SMTP in Python Flask
Set Up Project Directory
1. Create a directory for your Flask app:
2. Create a virtual environment to isolate dependencies
python -m venv venv
venv\Scripts\activate
3. Install Dependencies
You'll need to install Flask for the web server and Flask-Mail for handling email tasks. Optionally, you can also install python-dotenv for managing environment variables (like SMTP credentials).
pip install Flask Flask-Mail python-dotenv
Create a .env file
For security, we will store sensitive information like email credentials in a .env file. Create a .env file in your project directory:
nul > .env
4. Create the Flask App
Now, create a Python file for the Flask app, app.py.
from flask import Flask, request, jsonify
from flask_mail import Mail, Message
import os
from dotenv import load_dotenv
# Load environment variables from .env file
load_dotenv()
app = Flask(__name__)
# Configure the Flask-Mail extension
app.config['MAIL_SERVER'] = os.getenv('EMAIL_HOST')
app.config['MAIL_PORT'] = int(os.getenv('EMAIL_PORT'))
app.config['MAIL_USE_TLS'] = True
app.config['MAIL_USERNAME'] = os.getenv('EMAIL_USER')
app.config['MAIL_PASSWORD'] = os.getenv('EMAIL_PASSWORD')
app.config['MAIL_DEFAULT_SENDER'] = os.getenv('EMAIL_SENDER')
# Initialize Mail object
mail = Mail(app)
@app.route('/send-email', methods=['POST'])
def send_email():
try:
# Retrieve JSON data from the request
data = request.get_json()
message_body = data.get('message')
recipient_email = data.get('email')
if not message_body or not recipient_email:
return jsonify({'error': 'Missing message or email'}), 400
# Compose the email message
msg = Message(subject="Message from Flask App",
recipients=[recipient_email],
body=message_body)
# Send the email
mail.send(msg)
return jsonify({'success': True, 'message': 'Email sent successfully'}), 200
except Exception as e:
return jsonify({'error': str(e)}), 500
if __name__ == '__main__':
app.run(debug=True)
5. Run the Flask Application
Now that the app is set up, run it:
python app.py
6. Explanation:
Flask Configuration: We load email credentials from the .env file using the python-dotenv library and set up Flask-Mail to send emails via an SMTP server.
POST Route /send-email:
http://127.0.0.1:5000/send-email
This route expects a JSON request body with two fields:
message: The body/content of the email.
email: The recipient email address.
{
"message": "Hello, this is a test email from Flask!!",
"email": "romel.usigan25@gmail.com"
}
It uses smtplib to send the email via SMTP.
If something is missing or goes wrong, we send an error message in the response.
Sending Email:
We create a Message object from Flask-Mail, passing the subject, recipient, and body content.
The email is sent using mail.send(msg).
