Preparation Steps

Before writing code, you’ll need an active SMTP account from a provider like Gmail, Outlook, or QQ Mail. Gather the following details: SMTP server address, port number, your email address, and authentication credentials. For sceurity, many providers require enabling access for less secure apps (for older accounts) or generating an app-specific password (for two-factor authentication enabled accounts).

Sending Plain Text Emails

To send a basic text email, use Python’s smtplib for server communication and email modules to construct the message. Here’s a modified implementation:

import smtplib
from email.mime.text import MIMEText
from email.utils import formataddr

# SMTP Server Configuration
smtp_host = 'smtp.gmail.com'  # Replace with your provider's SMTP host
smtp_port = 587  # Common ports: 25 (unencrypted), 465 (SSL), 587 (TLS)
sender_email = 'your-account@example.com'
app_password = 'your-app-specific-password'  # Use app password for secure access
recipient_emails = ['colleague@example.com', 'client@example.com']

# Construct Email Content
email_body = 'This is an automated notification sent via Python. No action required unless you see this in error.'
message = MIMEText(email_body, 'plain', 'utf-8')
message['From'] = formataddr(('Automated Alert System', sender_email))
message['To'] = ', '.join(recipient_emails)
message['Subject'] = 'Python Automated Notification: System Update'

# Send the Email
try:
    with smtplib.SMTP(smtp_host, smtp_port) as server:
        server.starttls()  # Enable TLS encryption for secure transmission
        server.login(sender_email, app_password)
        server.sendmail(sender_email, recipient_emails, message.as_string())
        print('Plain text email sent successfully!')
except Exception as error:
    print(f'Failed to send email: {str(error)}')

Sending HTML Formatetd Emails

For more visually rich notifications, you can send HTML emails by adjusting the MIMEText content type. Here’s how to modify the message construction:

# Replace the message construction section with this
html_body = '''
<p>Hello Team,</p>
<p>Please be advised of the following system updates:</p>
<ul>
    <li>Server maintenance scheduled for 2 AM UTC on Friday</li>
    <li>New API endpoint now available for user data requests</li>
    <li>For details, visit our <a href="https://internal.example.com/updates">internal update portal</a></li>
</ul>
<p>Best regards,<br>The Automation Team</p>
'''
message = MIMEText(html_body, 'html', 'utf-8')
message['From'] = formataddr(('Automated Alert System', sender_email))
message['To'] = ', '.join(recipient_emails)
message['Subject'] = 'HTML Notification: Critical System Updates'

Key Notes:

• Most modern SMTP servers support HTML emails, but always test your HTML code in a browser to ensure proper rendering.
• Avoid using complex CSS that may not be supported by all email clients.

Adding Attachments to Emails

To include files like reports or logs, use the MIMEMultipart class to create a message with multiple parts. Here’s a complete example:

import smtplib
from email.mime.text import MIMEText
from email.mime.multipart import MIMEMultipart
from email.mime.base import MIMEBase
from email import encoders
from email.utils import formataddr

# SMTP Configuration (same as before)
smtp_host = 'smtp.example.com'
smtp_port = 587
sender_email = 'your-account@example.com'
app_password = 'your-app-specific-password'
recipient_emails = ['manager@example.com']

# Create Multipart Message
multipart_msg = MIMEMultipart()
multipart_msg['From'] = formataddr(('Report Automation', sender_email))
multipart_msg['To'] = ', '.join(recipient_emails)
multipart_msg['Subject'] = 'Weekly Performance Report Attached'

# Add Email Body
email_body = 'Please find the weekly performance report attached for your review.'
multipart_msg.attach(MIMEText(email_body, 'plain', 'utf-8'))

# Attach File
attachment_path = 'weekly_performance_report.pdf'
with open(attachment_path, 'rb') as file:
    attachment_part = MIMEBase('application', 'octet-stream')
    attachment_part.set_payload(file.read())
    encoders.encode_base64(attachment_part)
    attachment_part.add_header(
        'Content-Disposition',
        f'attachment; filename="{attachment_path}"'
    )
    multipart_msg.attach(attachment_part)

# Send the Email
try:
    with smtplib.SMTP(smtp_host, smtp_port) as server:
        server.starttls()
        server.login(sender_email, app_password)
        server.sendmail(sender_email, recipient_emails, multipart_msg.as_string())
        print('Email with attachment sent successfully!')
except Exception as error:
    print(f'Failed to send attachment email: {str(error)}')

Key Notes:

• Adjust the MIME type (application/octet-stream in this example) to match your file type (e.g., image/jpeg for images, text/csv for CSV files).
• For filenames with non-ASCII characters, use email.header.Header to ensure proper rendering across email clients.