Crystal SMTP Library

A lightweight SMTP client/server library for Crystal.
This library aims to provide simple and reliable SMTP functionality with minimal dependencies.

Status

🏗️ Work in Progress

• ✅ SMTP Client - Complete and working
• 🚧 SMTP Server - Planned, not yet implemented

Installation

1. Add the dependency to your shard.yml:

dependencies:
  smtp:
    github: alefunion/smtp

2. Run shards install

Usage

require "smtp"

# Initialize client
client = SMTP::Client.new("email-smtp.us-east-1.amazonaws.com")

begin
  # Authenticate
  client.authenticate("your_username", "your_password")

  # Send email
  client.send_email(
    from: "sender@yourdomain.com",
    to: "recipient@example.com",
    subject: "Test Email",
    body: "Hello from Crystal!"
  )
ensure
  client.close
end

Features

SMTP Client

• TLS support (STARTTLS)
• Authentication (LOGIN method)
• Basic email sending functionality
• Proper SMTP response handling
• Error handling with custom SMTP::Error class

SMTP Server (Coming Soon)

• Basic SMTP server implementation
• TLS support
• Authentication handlers
• Message processing hooks
• Custom routing rules