Gmail Bulk Mailer

A small desktop app that sends the HTML email in mail_content.html to every recipient listed in an Excel file.

Before you start

Install Python 3, then install the required packages from this project folder:

python -m pip install pandas openpyxl python-dotenv

tkinter is included with most standard Python installations. If the app does not open, reinstall Python and ensure the optional Tcl/Tk component is selected.

Set up Gmail credentials

This program sends through Gmail's SMTP server. Do not put your usual Google account password in the environment file. Use a Google App Password instead.

1. Enable 2-Step Verification for the Gmail/Google account that will send the emails: https://myaccount.google.com/security.
2. Open the App Passwords page: https://myaccount.google.com/apppasswords.
3. Create an app password (for example, name it Bulk Mailer).
4. Google will show a 16-character password. Copy it; it is shown only once.

If the App Passwords page is unavailable, 2-Step Verification may not be enabled, or the Google account administrator may have disabled app passwords.

Create the .env file

In the project folder, create a file named .env (no filename before the dot). You can copy .env.example and replace its values:

EMAIL=youraddress@gmail.com
EMAIL_PASSWORD=your_16_character_google_app_password

• EMAIL is the Gmail address that appears as the sender.
• EMAIL_PASSWORD is the App Password from the previous section. Spaces are optional; either format normally works.

The .env file is already ignored by Git, so keep it private and never share or commit it.

Prepare recipients

Create an Excel file (.xlsx or .xls) with a column whose header is exactly Email.

Email
person1@example.com
person2@example.com

Blank cells are skipped. The program will show an error if the Email column is missing.

Customize the email

• Edit mail_content.html to change the email design and message.
• Edit the msg["Subject"] value in main.py to set the email subject. It currently says add mail subject.

Run the app

From the project folder, run:

python main.py

Click Browse, select the recipient Excel file, and the app will send the email to each address in its Email column. The terminal prints each successful recipient, and the app displays a final total when it is done.

Notes

• Test with your own email address before sending to a full list.
• Gmail may limit or temporarily block high-volume sending. Use this only for recipients who have agreed to receive the message.
• Keep the .env, main.py, and mail_content.html files together in the project folder when running the program.