Spree uses ActionMailer to send transactional emails (eg. order confirmation, password reset, etc.) under the hood. You can use any SMTP server to send emails from your application. For production use we recommend using a service like SendGrid.

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Configuring SendGrid

Spree Starter comes with SendGrid pre-configured out of the box and you will need to set the following environment variables:
  • SENDGRID_API_KEY - Your SendGrid API key. Can be found in the SendGrid dashboard.
  • SENDGRID_DOMAIN - The domain you want to use for sending emails that was verified in SendGrid, eg. mystore.com.
If you’re not using Spree Starter you will need to add these code in your config/environments/production.rb file: 
  if ENV['SENDGRID_API_KEY'].present?
    ActionMailer::Base.smtp_settings = {
      user_name: 'apikey', # This is the string literal 'apikey', NOT the ID of your API key
      password: ENV['SENDGRID_API_KEY'], # This is the secret sendgrid API key which was issued during API key creation
      domain: ENV.fetch('SENDGRID_DOMAIN', Rails.application.routes.default_url_options[:host]),
      address: 'smtp.sendgrid.net',
      port: 587,
      authentication: :plain,
      enable_starttls_auto: true
    }
  end
Remember to verify the email address in SendGrid, you intend to use for sending emails, otherwise emails will be rejected.Read more about SendGrid sender verification
That’s it! You can now send emails from your application.