ruby send mails with 'mail'

example.rb

#!/usr/bin/env ruby
require 'mail'

def send_mail(content)
  mail = Mail.new do
    from      'mail@example.com'
    to        'recipient@domain.com'
    subject   "Subject"
    body      content
  end
  mail.delivery_method :sendmail
  mail.deliver
end

send_mail('Hallo :)')