Monitor Correios (correios.com.br) website for update on shipping information. Set up FROM_EMAIL and TO_EMAIL and just put it in your crontab or do a while;true bash loop: $ ruby correios.rb <TRACKING_ID>

config.rb

#!/usr/bin/ruby

require 'mail'

GMAIL_USERNAME = "username"
GMAIL_PASSWORD = "password"

options = { :address              => "smtp.gmail.com",
            :port                 => 587,
            :domain               => 'gmail.com',
            :user_name            => GMAIL_USERNAME,
            :password             => GMAIL_PASSWORD,
            :authentication       => 'plain',
            :enable_starttls_auto => true  }

Mail.defaults do
  delivery_method :smtp, options
end

correios.rb

require 'fileutils'
require './config.rb' # Put your Mail configuration here (e.g. localhost, gmail, etc)

FROM_EMAIL = "[email protected]"
TO_EMAIL   = "[email protected]"

def mail(from_email, to_email, content)
  Mail.deliver do
    from    from_email
    to      to_email
    subject 'Correios: Atualizacao!'
    body    content
  end
end

SHIPPING_ID = ARGV[0]
TRACKING_URL = "http://websro.correios.com.br/sro_bin/txect01$.QueryList?P_LINGUA=002&P_TIPO=002&P_COD_LIS=#{SHIPPING_ID}"
current_version = "correios-current.html"
last_version = "correios-last.html"

# This is where magic happens!
print "Checking for update... "
FileUtils.touch current_version
FileUtils.touch last_version
`wget -qO #{current_version} '#{TRACKING_URL}'`
diff = `diff #{current_version} #{last_version}`
unless diff.empty?
  print "Found! Sending mail... "
  mail(FROM_EMAIL, TO_EMAIL, TRACKING_URL)
end
`mv #{current_version} #{last_version}`
puts "[ OK ]"