Sending simple emails in Flask - Mini Project: Build & Apply

Sending simple emails

📖 Scenario: You are building a small Flask web app that can send a simple email when a user submits a form. This is useful for contact forms or notifications.

🎯 Goal: Create a Flask app that sets up email configuration, defines a route to send an email, and sends a simple email message.

📋 What You'll Learn

Create a Flask app instance

Configure email server settings using Flask-Mail

Define a route /send-email that sends an email

Send a simple email with subject, sender, recipient, and body

💡 Why This Matters

🌍 Real World

Sending emails is common in web apps for notifications, password resets, and contact forms.

💼 Career

Understanding how to send emails programmatically is a key skill for backend web developers.

1

Set up Flask app and Flask-Mail

Import Flask and Mail from flask_mail. Create a Flask app instance called app. Then create a Mail instance called mail using app.

Flask

from flask import Flask
from flask_mail import Mail

# Create Flask app instance
app = Flask(__name__)

# Create Mail instance
mail = Mail(app)

Need a hint?

Use app = Flask(__name__) to create the app. Then pass app to Mail().

2

Configure email server settings

Add these configuration settings to app.config: MAIL_SERVER set to 'smtp.example.com', MAIL_PORT set to 587, MAIL_USE_TLS set to True, MAIL_USERNAME set to '[e-mail]', and MAIL_PASSWORD set to 'password123'.

Flask

from flask import Flask
from flask_mail import Mail

app = Flask(__name__)

# Configure email server settings
app.config['MAIL_SERVER'] = 'smtp.example.com'
app.config['MAIL_PORT'] = 587
app.config['MAIL_USE_TLS'] = True
app.config['MAIL_USERNAME'] = '[e-mail]'
app.config['MAIL_PASSWORD'] = 'password123'

mail = Mail(app)

Need a hint?

Set each config key on app.config exactly as shown.

3

Create a route to send an email

Import Message from flask_mail. Define a route /send-email with a function send_email. Inside it, create a Message object with subject 'Hello', sender '[e-mail]', recipients list with '[e-mail]', and body 'This is a test email.'. Then send the message using mail.send(msg).

Flask

from flask import Flask
from flask_mail import Mail
from flask_mail import Message

app = Flask(__name__)
app.config['MAIL_SERVER'] = 'smtp.example.com'
app.config['MAIL_PORT'] = 587
app.config['MAIL_USE_TLS'] = True
app.config['MAIL_USERNAME'] = '[e-mail]'
app.config['MAIL_PASSWORD'] = 'password123'
mail = Mail(app)

@app.route('/send-email')
def send_email():
    # Create Message object
    msg = Message(subject='Hello', sender='[e-mail]', recipients=['[e-mail]'], body='This is a test email.')
    # Send email
    mail.send(msg)
    return 'Email sent!'

Need a hint?

Use @app.route('/send-email') to define the route. Create the Message with the exact subject, sender, recipients, and body. Then call mail.send(msg).

4

Run the Flask app

Add the standard Flask app run block at the bottom: if __name__ == '__main__': and inside it call app.run(debug=True).

Flask

from flask import Flask
from flask_mail import Mail
from flask_mail import Message

app = Flask(__name__)
app.config['MAIL_SERVER'] = 'smtp.example.com'
app.config['MAIL_PORT'] = 587
app.config['MAIL_USE_TLS'] = True
app.config['MAIL_USERNAME'] = '[e-mail]'
app.config['MAIL_PASSWORD'] = 'password123'
mail = Mail(app)

@app.route('/send-email')
def send_email():
    msg = Message(subject='Hello', sender='[e-mail]', recipients=['[e-mail]'], body='This is a test email.')
    mail.send(msg)
    return 'Email sent!'

if __name__ == '__main__':
    # Run the app
    app.run(debug=True)

Need a hint?

Add the standard Flask run block at the end to start the app in debug mode.