Send Automated Emails with Python

📋 What You’ll Need

Python 3.7 or higher
A Gmail account
VS Code or any editor
Basic Python knowledge
Internet connection
30 minutes

Email automation powers everything from welcome emails to weekly reports to alert systems. Python's smtplib is built-in — no pip install needed. Let's go.

Enable Gmail App Password

Gmail requires an App Password instead of your regular password when using SMTP. Here's how to set it up:

Go to your Google Account → Security
Enable 2-Step Verification (required)
Go back to Security → search "App passwords"
Select app: Mail, device: Other (name it "Python")
Click Generate — copy the 16-character password

🔒 Keep it safe: Treat this App Password like your real password. Don't commit it to GitHub. Store it in an environment variable or a .env file.

Send your first plain text email

Create email_sender.py. Here's the minimum working email script:

import smtplib
from email.mime.text import MIMEText

SENDER = 'your.email@gmail.com'
PASSWORD = 'your-app-password'
RECIPIENT = 'recipient@example.com'

msg = MIMEText('Hello! This email was sent by Python.')
msg['Subject'] = 'Test from Python 🌟'
msg['From'] = SENDER
msg['To'] = RECIPIENT

with smtplib.SMTP_SSL('smtp.gmail.com', 465) as server:
server.login(SENDER, PASSWORD)
server.send_message(msg)
print('Email sent!')

Run this with python email_sender.py. Check your inbox — it should arrive within seconds.

Send a styled HTML email

Plain text works, but HTML emails look professional. Use MIMEMultipart to send both versions (email clients pick the best one):

from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText

msg = MIMEMultipart('alternative')
msg['Subject'] = 'Weekly Report 📊'
msg['From'] = SENDER
msg['To'] = RECIPIENT

plain = 'Your weekly report is ready.'
html = '''<html><body>
<h2 style="color:#162447">Weekly Report 📊</h2>
<p>Here is your summary for this week:</p>
<ul><li>Tasks completed: <strong>12</strong></li>
<li>Emails sent: <strong>47</strong></li></ul>
<a href="https://example.com" style="background:#F59C0D;color:#fff;padding:10px 20px;border-radius:6px;text-decoration:none">View Full Report</a>
</body></html>'''

msg.attach(MIMEText(plain, 'plain'))
msg.attach(MIMEText(html, 'html'))

The 'alternative' type tells email clients to show the HTML version if they support it, or fall back to plain text.

Add a file attachment

Send a file along with the email using MIMEBase:

from email.mime.base import MIMEBase
from email import encoders
import os

filename = 'report.pdf'
with open(filename, 'rb') as f:
part = MIMEBase('application', 'octet-stream')
part.set_payload(f.read())
encoders.encode_base64(part)
part.add_header('Content-Disposition', f'attachment; filename={os.path.basename(filename)}')
msg.attach(part)

💡 Any file works: Change the filename to a .csv, .xlsx, .png or any other file type. The octet-stream MIME type works for everything.

Send to multiple recipients

Loop through a list of recipients to send personalised bulk emails:

recipients = [
('Alice', 'alice@example.com'),
('Bob', 'bob@example.com'),
]

with smtplib.SMTP_SSL('smtp.gmail.com', 465) as server:
server.login(SENDER, PASSWORD)
for name, email in recipients:
msg['To'] = email
msg.replace_header('Subject', f'Hi {name}, your report is ready')
server.send_message(msg)
print(f'Sent to {name}')

Output

Sent to Alice
Sent to Bob

Store credentials safely with environment variables

Never hardcode passwords in your script. Use environment variables instead:

import os

SENDER = os.environ['EMAIL_SENDER']
PASSWORD = os.environ['EMAIL_PASSWORD']

Set them in your terminal before running:

# Windows (PowerShell)
$env:EMAIL_SENDER = "your@gmail.com"
$env:EMAIL_PASSWORD = "your-app-password"

# Mac/Linux
export EMAIL_SENDER="your@gmail.com"
export EMAIL_PASSWORD="your-app-password"

🔒 Even better: Use a .env file with the python-dotenv library (pip install python-dotenv) to load variables automatically.

Schedule emails to run automatically

Use Python's schedule library to send emails on a timer:

import schedule, time

def send_daily_report():
print('Sending daily report...')
# put your email code here

schedule.every().day.at('08:00').do(send_daily_report)

while True:
schedule.run_pending()
time.sleep(60)

Install it first: pip install schedule. Run the script and it will send your email automatically at 8am every day while it's running.

🎉

You did it!

You can now send plain text emails, styled HTML emails, file attachments, and bulk personalised emails — all from Python. This is the foundation of automated reports, alert systems, and marketing tools.

← Browse More Tutorials

🚀 Take It Further

Load recipients from a CSV file
Send alerts when a Python script fails (wrap in try/except)
Add inline images to HTML emails with MIMEImage
Use SendGrid or Mailgun API for higher sending limits
Build a daily news digest emailer using web scraping + email

← All Tutorials

💌 Send Automated Emails with Python

🎯 What You’ll Build

📋 What You’ll Need

Enable Gmail App Password

Send your first plain text email

Send a styled HTML email

Add a file attachment

Send to multiple recipients

Store credentials safely with environment variables

Schedule emails to run automatically

You did it!

🚀 Take It Further

💌 Send Automated Emails with Python

🎯 What You’ll Build

📋 What You’ll Need

Enable Gmail App Password

Send your first plain text email

Send a styled HTML email

Add a file attachment

Send to multiple recipients

Store credentials safely with environment variables

Schedule emails to run automatically

You did it!

🚀 Take It Further

Found something wrong?

Thanks — got it!