move all messages (ruby: net/imap)

gistfile1.rb

require 'net/imap'

imap = Net::IMAP.new('example.com')
imap.authenticate('LOGIN', '[email protected]', 'password')
imap.select('INBOX')
if not imap.list('INBOX', 'testfolder')
  imap.create('INBOX.testfolder')
end
imap.expunge
imap.uid_search(["FROM", "[email protected]"]).each_with_index do |message_id, i|
  puts(message_id)
  imap.uid_copy(message_id, "INBOX.testfolder")
  imap.uid_store(message_id, "+FLAGS", [:Deleted])
  if i % 100 == 0
    imap.expunge
  end
end
imap.expunge
imap.logout