mail-sender

Table of Contents

• Description
• Features
• Technologies Used
• Getting Started
  • Prerequisites
  • Installation
• Usage
  • REST API
    • Request body
      • Example Request
  • RabbitMQ's Integration
    • Example Message
• Exception Handling
• License

Description

This is a Spring Boot application for sending emails via SMTP. It supports both asynchronous and synchronous email sending, handles attachments, and integrates with RabbitMQ for message queuing.

Features

• Send emails with optional CC and BCC addresses.
• Send emails with or without attachments.
• Support for both plain text and HTML email bodies.
• Asynchronous email sending for improved performance.
• RabbitMQ's integration for sending emails through message queues.
• Error handling and dead-letter queue support for failed messages.

Technologies Used

• Spring Boot - A framework for building Java applications.
• Spring Mail - For sending emails.
• Spring AMQP - For message queuing and handling.

Getting Started

Prerequisites

• JDK 21 or higher
• RabbitMQ server
• SMTP server for sending emails

Installation

1. Clone the repository:

   git clone https://github.com/nenadjakic/mail-sender.git
   cd mail-sender
   

2. Configure the application properties: Update the application.properties with your SMTP server and RabbitMQ configuration.

   mail-sender.from=no-reply@example.com
   mail-sender.queue-name= mail_queue
   mail-sender.dead-letter-queue-name= mail_dead_letter_queue
   
   spring.mail.host=smtp.example.com
   spring.mail.port= 587
   spring.mail.username= your-email@example.com
   spring.mail.password= your-email-password
   
   spring.rabbitmq.host=http://example.com
   spring.rabbitmq.port=5672
   spring.rabbitmq.username=guest
   spring.rabbitmq.password=guest

3. Build the project:

   ./gradlew clean build
   

4. Run the project:

   ./gradlew bootRun
   

Usage

REST API

You can send emails via the following API endpoint:

• POST /api/mail/send

Request Body

The API accepts multipart form data. The mailDto part is a JSON object that contains the email details, and attachments is an optional part for file uploads.

• to - List of recipient email addresses.
• cc - List of CC email addresses (optional).
• bcc - List of BCC email addresses (optional).
• subject - Email subject.
• body - Email body (HTML or plain text).
• isHtml - Boolean indicating if the body is HTML.

Example Request:

curl -X POST "http://localhost:8080/api/mail/send" \
  -H "Content-Type: multipart/form-data" \
  -F 'mailDto={"to":["recipient@example.com"], "subject":"Test Email", "body":"This is a test email.", "isHtml":false}' \
  -F "attachments=@/path/to/file.txt"

RabbitMQ's Integration

Emails can also be sent by publishing a message to RabbitMQ. The service listens for messages on the configured queue (mail-sender.queue-name).

• Queue: ${mail-sender.queue-name}

Example Message

The message should be in JSON format with the same structure as the MailDto object.

```json
{
  "to": ["recipient@example.com"],
  "cc": null,
  "bcc": null,
  "subject": "Test Email",
  "body": "This is a test email.",
  "isHtml": false
}
```

Exception Handling

If an error occurs while sending the email, the message is routed to a **dead-letter queue ** (${mail-sender.dead-letter-queue-name}), and an error is logged.

License

This project is licensed under the Apache License - see the LICENSE file for details.