Email with attachments in Flask - Mini Project: Build & Apply

Email with attachments

📖 Scenario: You are building a simple Flask web app that can send emails with attachments. This is useful for sending reports, images, or documents directly from your app.

🎯 Goal: Create a Flask app that sends an email with an attachment using Flask-Mail.

📋 What You'll Learn

Create a Flask app instance

Configure Flask-Mail with SMTP server details

Create a route to send an email with an attachment

Use Flask-Mail's Message class to add subject, sender, recipients, body, and attachment

💡 Why This Matters

🌍 Real World

Sending emails with attachments is common in web apps for notifications, reports, invoices, or sharing files directly from the app.

💼 Career

Understanding how to send emails with attachments using Flask-Mail is useful for backend web developers working on user communication features.

1

Set up Flask app and Flask-Mail

Create a Flask app instance called app and initialize Flask-Mail with it using mail = Mail(app). Import Flask and Mail from flask and flask_mail respectively.

Flask

from flask import Flask
from flask_mail import Mail

# Your code here

Need a hint?

Remember to import Flask and Mail, then create app and mail.

2

Configure Flask-Mail SMTP settings

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

Flask

from flask import Flask
from flask_mail import Mail

app = Flask(__name__)

# Your code here

mail = Mail(app)

Need a hint?

Set all required mail config keys in app.config before initializing mail.

3

Create a route to send email with attachment

Create a Flask route @app.route('/send-email') with a function send_email(). Inside it, import Message from flask_mail. Create a Message object with subject 'Hello', sender '[e-mail]', recipients list with '[e-mail]', and body 'This is a test email with attachment.'. Attach a file named 'test.txt' with content 'This is the content of the file.' and MIME type 'text/plain' using msg.attach().

Flask

from flask import Flask
from flask_mail import Mail

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)

# Your code here

Need a hint?

Use @app.route to create the route and Message to build the email. Use attach() to add the file.

4

Send the email and return confirmation

Inside the send_email() function, send the email using mail.send(msg). Then return the string 'Email sent!' to confirm the action.

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 with attachment.')
    msg.attach('test.txt', 'text/plain', 'This is the content of the file.')
    # Your code here

Need a hint?

Use mail.send(msg) to send the email and return a confirmation string.