Spring Boot Email Sender

A Java Spring Boot application to send emails with attachments to multiple, individually-selected recipients managed via a simple text file.

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🎯 Overview

Sharing information within a community or group should be seamless, but managing recipient lists can be a hassle. Email Sender is a mini-project built to solve this. It's an efficient Java Spring Boot application that allows a user to send customized emails—with file attachments—to a list of recipients that is dynamically loaded from a simple text file.

This project demonstrates a full-stack, self-contained application using Spring Boot for the backend logic and Thymeleaf for rendering a simple, user-friendly HTML interface.

✨ Key Features

• ✅ Dynamic Recipient Management: Reads email addresses from a .txt file and displays them as a checklist.
• ✅ Selective & Bulk Messaging: Gives the user fine-grained control to message individuals or the entire list with a "Select All" option.
• ✅ File Attachments: Effortlessly attach files (up to 10MB by default) to your emails.
• ✅ User-Friendly Interface: A simple HTML form for composing the subject and message body.
• ✅ Secure & Configurable: Email credentials are kept out of the code and managed in the application.properties file for security and ease of setup.

📸 Screenshots

Main Interface - Recipient Selection & Composition
<-- Add a screenshot of your main UI here, showing the checkboxes, form fields, and file attachment button. -->

Email Sent - Success Message
<-- Add a screenshot of the success confirmation page here. -->

🛠️ Technology Stack

Technology	Icon	Description
Java		Core programming language and platform.
Spring Boot		Framework for building the robust backend and web application.
JavaMail API		The underlying API used for sending emails via SMTP protocol.
Thymeleaf		A modern server-side Java template engine for rendering the HTML user interface.
Maven		Dependency management and project build tool.
HTML5/CSS		For structuring and styling the frontend pages.

🚀 Getting Started

This project is not publicly deployed and is intended to be run on a local machine. Follow these instructions to get it set up.

Prerequisites

• Java Development Kit (JDK) 11 or newer
• Apache Maven
• An IDE (like IntelliJ IDEA, Eclipse, or VS Code)
• An active email account (e.g., Gmail) to use as the sender.

Installation & Configuration

1. Clone the repository:

   git clone [https://github.com/_YOUR_USERNAME_/_YOUR_REPOSITORY_.git](https://github.com/_YOUR_USERNAME_/_YOUR_REPOSITORY_.git)
   cd _YOUR_REPOSITORY_

2. Configure Email & Attachment Properties: Open src/main/resources/application.properties. This file holds all the necessary configurations. Update it with your sender email credentials and attachment settings.

   # Spring Mail Properties
   spring.mail.host=smtp.gmail.com
   spring.mail.port=587
   spring.mail.username=your-email@gmail.com
   spring.mail.password=your-app-password # CRITICAL: Use an App Password, not your regular password!
   
   spring.mail.properties.mail.smtp.auth=true
   spring.mail.properties.mail.smtp.starttls.enable=true
   
   # File Upload Properties
   spring.servlet.multipart.enabled=true
   spring.servlet.multipart.max-file-size=10MB
   spring.servlet.multipart.max-request-size=10MB

   🔒 Gmail Security Note: If you are using a Gmail account, you must enable 2-Factor Authentication and generate an "App Password". Using your regular Google account password will fail. Learn how to create App Passwords here.

3. Create the Recipient List: In the src/main/resources/ directory, create a file named emails.txt. Add one email address per line. The application will read from this file.

   example.user1@domain.com
   test.user2@email.org
   another.recipient@provider.net

Running the Application

1. Build the project using Maven:

   mvn clean install

2. Run the Spring Boot application:

   mvn spring-boot:run

   Alternatively, you can run the main application class YourApplicationNameApplication.java directly from your IDE.

3. Access the application: Open your web browser and navigate to http://localhost:8080.

📂 Project Structure

Here are the key files and directories in the project: /src
├──/main
│ ├──/java/... # Main application Java source code (Controllers, Services)
│ └──/resources
│ ├──/templates # HTML files for the UI (e.g., index.html)
│ ├── emails.txt # Your list of recipient emails
│ └── application.properties # Application and email configuration
└──/test
pom.xml # Maven project configuration

📜 License

This project is licensed under the MIT License. See the LICENSE file for more details.

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Developed with ❤️ and Java by Bhargava A