Python for Trading & Investing: Send email from Gmail using Python

Configuration of Gmail

As of May 30, 2022, Google no longer supports the use of third-party apps or devices which ask you to sign in to your Google Account using only your username and password. Here is the note on Google Policy on less secure apps.

Step 1:

Step 2:

Ensure that two step verification is switched on:

Step 3:

Click on 'App passwords'. Sign in with email and password. choose the app as mail

Step 4:

Click on GENERATE. Choose the app password thus generated (highlighted in yellow). Follow the instructions on 'how to use it'

Note: Please note that once we enable the 2-Step Verification, the "Less secure app access" automatically stands disabled (as shown in figure below). All the above steps can be done away with if you just enable the "Less secure app access"

Python Code for email without an attachment

Here is the python code to send a simple email:

# Imports for the program
import smtplib
 
# create SMTP session
server = smtplib.SMTP('smtp.gmail.com', 587) # smtp address for gmail and port number
 
# start  Transport Layer Security(TLS)
server.starttls()

# Sender email and pass
sender_email = "test@gmail.com"
sender_password = "testpass"

# Authentication
server.login(sender_email, sender_password)

# Receiver email's
receiver_email = ['test1@gmail.com', 'test2@gmail.com']
email_message_string = '''Subject: Mail from Pav
This email is a test mail that is sent  using Python'''

# sending the mail
server.sendmail(sender_email, receiver_email, email_message_string)
 
# terminating the session
server.quit()

Python code to send HTML email with the email.mime module

We generally use Multipurpose Internet Mail Extensions (MIME) standard to achieve this. MIME is an Internet standard that extends the format of email messages to support text in character sets other than ASCII, as well as attachments of audio, video, images, and application programs

These are the steps that we take:

Import modules
Define the HTML document
Set up the email addresses and password
Create a MIMEMultipart class, and set up the From, To, Subject fields
Attach the html doc defined earlier, as a MIMEText html content type to the MIME message
Convert the email message as string
Connect to the Gmail SMTP server and send Email

# Imports used in program
import smtplib, ssl
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText

# Define the HTML document
html = '''
    <html>
        <body>
            <h1>Monthy Report</h1>
            <p>Hello Shawn, welcome to your monthly report!</p>
        </body>
    </html>
    '''

# Set up the email addresses and password. Please replace below with your email address and password
sender_email = "test@gmail.com"
sender_password = "testpass"
receiver_email = 'test1@gmail.com'

# Create a MIMEMultipart class, and set up the From, To, Subject fields
email_message = MIMEMultipart()
email_message['From'] = sender_email
email_message['To'] = receiver_email
email_message['Subject'] = 'Email with Monthly report'

# Attach the html doc defined earlier, as a MIMEText html content type to the MIME message
email_message.attach(MIMEText(html, "html"))
# Convert it as a string
email_string = email_message.as_string()

# Connect to the Gmail SMTP server and Send Email
context = ssl.create_default_context()
with smtplib.SMTP_SSL("smtp.gmail.com", 465, context=context) as server:
    server.login(sender_email, sender_password)
    server.sendmail(sender_email, receiver_email, email_string)

Python Code to send an email with attachment

Let us modify the above code to include an attachment.

# Imports used in program
import smtplib, ssl
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from email.mime.application import MIMEApplication

# Define the HTML document
html = '''
    <html>
        <body>
            <h1>Monthly Report</h1>
            <p>Hello Shawn Johnson, welcome to your monthly report!</p>
        </body>
    </html>
    '''

# Define a function to attach files as MIMEApplication to the email
def attach_file_to_email(email_message, filename):
    # Open the attachment file for reading in binary mode, and make it a MIMEApplication class
    with open(filename, "rb") as f:
        file_attachment = MIMEApplication(f.read())
    # Add header/name to the attachments    
    file_attachment.add_header(
        "Content-Disposition",
        f"attachment; filename= {filename}",
    )
    # Attach the file to the message
    email_message.attach(file_attachment)

# Set up the email addresses and password. Please replace below with your email address and password
sender_email = "test@gmail.com"
sender_password = "pass"
receiver_email = "test2@gmail.com"

# Create a MIMEMultipart class, and set up the From, To, Subject fields
email_message = MIMEMultipart()
email_message['From'] = sender_email
email_message['To'] = receiver_email
email_message['Subject'] = 'Report email'

# Attach the html doc defined earlier, as a MIMEText html content type to the MIME message
email_message.attach(MIMEText(html, "html"))

# Add attachment
attach_file_to_email(email_message, 'TestAttachment.txt')

# Convert it as a string
email_string = email_message.as_string()

# Connect to the Gmail SMTP server and Send Email
context = ssl.create_default_context()
with smtplib.SMTP_SSL("smtp.gmail.com", 465, context=context) as server:
    server.login(sender_email, sender_password)
    server.sendmail(sender_email, receiver_email, email_string)

Python for Trading & Investing

21 November 2022

Send email from Gmail using Python