SMTP in Ruby
Ruby developers have multiple options for sending emails using SMTP:
- The net/http module from the standard library: The net/http module provides a light-weight and low-level solution for sending emails via SMTP. While it's useful for sending simple email messages, it can be too verbose if you're planning to send HTML emails with attachments and custom headers.
- The Mail gem: Mail is an internet library for Ruby that is designed to handle email generation, parsing and sending in a simple, rubyesque manner. It's suitable for email-heavy applications that send complex emails with custom templates and (inline) attachments.
- ActionMailer: ActionMailer is part of Ruby on Rails and is used for sending emails. It provides a way to make email sending simple and efficient. This should be your go-to choice if your application is developed using Ruby on Rails.
Prerequisites
- Ensure that you have Ruby installed on your system.
- You have created and verified your domain on AhaSend.
- You have created SMTP credentials (username and password) for authentication.
Sending with the Ruby standard library
The net/smtp library is part of Ruby's standard library, offering a lower-level interface to send emails.
require 'net/smtp'
message = <<~MESSAGE_END
From: Your Name
To: Recipient Name
Subject: SMTP Test Email
Date: #{Time.now.rfc2822}
This is a test email sent using net/smtp in Ruby.
MESSAGE_END
smtp_settings = {
address: 'send.ahasend.com',
port: 587,
domain: 'domain.com', # your domain
user_name: 'YOUR_SMTP_USERNAME',
password: 'YOUR_SMTP_PASSWORD',
authentication: 'plain',
enable_starttls_auto: true
}
Net::SMTP.start(
smtp_settings[:address],
smtp_settings[:port],
smtp_settings[:domain],
smtp_settings[:user_name],
smtp_settings[:password],
smtp_settings[:authentication]
) do |smtp|
smtp.enable_starttls
smtp.send_message message, '[email protected]', '[email protected]'
end[email protected], YOUR_SMTP_USERNAME and YOUR_SMTP_PASSWORD with an email address from your domain (that is added to your AhaSend account), and your actual SMTP credential username and password.Sending with the Mail gem
The Mail gem is a library that uses net/smtp and other networking libraries from the standard library internally for all its networking actions, and provides a high-level interface for parsing, generating and sending email messages using Ruby.
require 'mail'
Mail.defaults do
delivery_method :smtp, {
address: 'send.ahasend.com',
port: 587,
user_name: 'YOUR_SMTP_USERNAME',
password: 'YOUR_SMTP_PASSWORD',
authentication: 'plain',
enable_starttls_auto: true
}
end
mail = Mail.new do
from '[email protected]'
to '[email protected]'
subject 'Here is the HTML message with an attachment'
html_part do
content_type 'text/html; charset=UTF-8'
body '<h1>This is HTML content</h1><p>This is a paragraph in HTML.</p>'
end
add_file '/path/to/attachment.jpg'
end
mail.deliver![email protected], YOUR_SMTP_USERNAME, YOUR_SMTP_PASSWORD and /path/to/attachment.jpg with the appropriate values.Sending emails with ActionMailer
ActionMailer is part of the Ruby on Rails framework and provides a simple yet customizable way for working with and sending emails. If you're using Ruby on Rails to develop your application, ActionMailer is your best choice for sending emails.
To get started, configure your SMTP settings in config/environments/production.rb (or development.rb for testing):
config.action_mailer.delivery_method = :smtp
config.action_mailer.smtp_settings = {
address: 'send.ahasend.com',
port: 587,
domain: 'example.com', # your domain
user_name: 'YOUR_SMTP_USERNAME',
password: 'YOUR_SMTP_PASSWORD',
authentication: 'plain',
enable_starttls_auto: true
}Create an HTML view for the email in app/views/user_mailer/welcome_email.html.erb:
<!DOCTYPE html>
<html>
<head>
<meta content='text/html; charset=UTF-8' http-equiv='Content-Type' />
</head>
<body>
<h1>Welcome to My Awesome Site</h1>
<p>
You have successfully signed up to example.com,
your username is: <%= @user.username %>.<br>
</p>
</body>
</html>Now create a mailer class with an HTML view and optionally specify the attachments:
# app/mailers/user_mailer.rb
class UserMailer < ActionMailer::Base
default from: '[email protected]'
def welcome_email(user)
attachments['filename.jpg'] = File.read('/path/to/attachment.jpg')
mail(to: user.email, subject: 'Welcome to My Awesome Site') do |format|
format.html { render 'another_template' }
end
end
end[email protected], YOUR_SMTP_USERNAME, YOUR_SMTP_PASSWORD and /path/to/attachment.jpg with the appropriate values.These libraries and gems are quite powerful and flexible, supporting a wide range of features from simple plaintext emails to complex messages with HTML content and attachments. This guide covered the basics to get you started. For more advanced features and options, please refer to the official documentation:
- net/smtp: https://github.com/ruby/net-smtp
- Mail gem: https://github.com/mikel/mail
- ActionMailer: https://guides.rubyonrails.org/action_mailer_basics.html
