text: import mailbox
  
  mbox = mailbox.mbox('example.mbox')
  mbox.lock()
  try:
      to_remove = []
      for key, msg in mbox.iteritems():
          if '2' in msg['subject']:
              print('Removing:', key)
              to_remove.append(key)
      for key in to_remove:
          mbox.remove(key)
  finally:
      mbox.flush()
      mbox.close()
  
  print(open('example.mbox', 'r').read())
  