Here's a basic example of how to use the Mail gem without action mailer on rails.

mail.rb

recipients = ['email@example.com']

mail_body = <<-HTML
  Hello world!
HTML

mail = Mail.new do
  delivery_method(
    :smtp,
    :address        => "address",
    :port           => "port",
    :authentication => :plain,
    :user_name      => "username",
    :password       => "password",
    :domain         => "domain"
  )

  from            'John Doe <john@doe.com>'
  to              'email@sample.com'
  bcc             user_emails
  subject         'Hi this is a test email'
  body            mail_body
end