Imap mail statistic with Ruby

imap-stats.rb

require "net/imap"
require "progressbar" 
require "active_support/all"  # sort_by!

class Array
  def histogram ; self.sort.inject({}){|a,x|a[x]=a[x].to_i+1;a} ; end
end

server   = "mailserver.com"
username = "mail@mailserver.com"
password = "password"

boxes = ["INBOX"]  # list all the IMAP folders to include in the calculations
imap = Net::IMAP.new(server)
imap.login(username, password)

# loop through all boxes, adding all mail-ids to the list
mail_ids = boxes.inject([]) do |sum, box|
  imap.select("INBOX")
  sum += imap.search(["ALL"])
end

puts "Found #{mail_ids.count} Mails in Boxes #{boxes.join(", ")}. Now Fetching Mail Headers..."

# new progressbar
pbar = ProgressBar.new "mails:", mail_ids.count

most = mail_ids.map do |id|
  pbar.inc
  # the sender is somewhat deep inside the mail...
  sender = imap.fetch(id, "ENVELOPE").first.attr["ENVELOPE"].sender.first
  "#{sender.mailbox}@#{sender.host}"
end.histogram

pbar.finish
most = most.to_a.sort_by{|address,count| -count}
puts most.map{|address,count| "#{address}; #{count}"}