The final step in the guide to backing up a Gmail account is now posted. As seen in the rest of the guide, it is a variation on how to pop a POP3 mailbox using poplib. Consequently, it tends to be pretty straightforward. If, however, you find yourself wondering why things are implemented as they are, check out "Retrieving POP3 Email with poplib" first. Then, failing that, see the write-up on "Using poplib to Access a POP3 Mail Server", in the Python Library section of the site.