🔲Resend

This guide outlines how to install and configure the Resend Gem for sending transactional emails in your Lightning Rails project.

Step 1: Create a Resend Account

1. Go to the Resend website.

2. Sign up and create an account to access your API key.

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Step 2: Add the Resend Gem

1. Open your Gemfile.

2. Add the Resend gem in your Gemfile:

   gem "resend"

3. Run bundle install in your terminal to install the gem.

   bundle install

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Step 3: Configure Your API Key

1. Locate your API key from the Resend dashboard.

2. Add the API key to your .env file:

   RESEND_API_KEY="re_***************"

3. Ensure you have the .env file setup as specified in the quickstart guide.

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Step 4: Set Up Action Mailer

1. Development Environment: Open config/environments/development.rb and set the delivery method to :letter_opener for testing emails locally (The Gem is already installed in the boilerplate):

   config.action_mailer.delivery_method = :letter_opener

2. Production Environment: Open config/environments/production.rb and set the delivery method to :resend:

   rubyCopy codeconfig.action_mailer.delivery_method = :resend

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(Optional) Step 5: Create Your First Mailer

1. Generate a new mailer:

   rails generate mailer UserMailer

2. Open the newly created file app/mailers/user_mailer.rb and define a mailer method. For example:

   class UserMailer < ApplicationMailer
     def welcome_email
       @user = params[:user]
       mail(to: @user.email, subject: "Welcome to Our App!")
     end
   end

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Step 6: Add HTML Content for the Email

1. Create a corresponding view file for the mailer:

   • Path: app/views/user_mailer/welcome_email.html.erb

   • Content example:

     htmlCopy code<h1>Welcome to Our App, <%= @user.name %>!</h1>
     <p>We’re excited to have you on board.</p>

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Step 7: Initialize and Send the Mailer

1. Open the Rails console:

   rails console

2. Initialize the mailer with a sample user object:

   u = User.new(name: "Derich", email: "[e-mail]")
   mailer = UserMailer.with(user: u).welcome_email

3. Send the email:

   mailer.deliver_now!

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Step 8: Verify the Email

• Check the recipient's inbox to confirm the email has been sent successfully.

• If testing in development, verify the email opens correctly using the letter_opener gem.

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That's it! You’ve successfully set up the Resend Gem for sending transactional an marketing emails in your Lightning Rails project, you can enjoy 100 free emails per month.