title: Reading mail from mbox folder using python
body: <p>I want to read mails from a mbox file and do some action based on that. I don't want to write/modify the mbox file but it will be modified by another process (Mostly adding new mails). </p>
  
  <p>I am reading this documentation. <a href="http://docs.python.org/library/mailbox.html#mailbox.mbox" rel="nofollow">http://docs.python.org/library/mailbox.html#mailbox.mbox</a></p>
  
  <p>But I don't understand the following</p>
  
  <ol>
  <li>Should I call lock() before reading the mail? (I am not writing to
  the file) </li>
  <li>Is there anyway I can get a callback when other process
  (thunderbird) modifies the file? </li>
  <li>Is the changes in the file reflected in the mbox object? I mean, after I create the mbox object, if a new mail is added to the file, will I access the message using the object? Or should I create a new object again?</li>
  </ol>
  
  <p>PS: I am not allowed to install any plugins of thunderbird:(</p>