'A dictionary of (name, MailFolder)-tuples.
Default folders: inbox, trash, spam, receipts, ...'

@property
def folders(self):

    if (self._folders is None):
        (status, response) = self.imap4.list()
        self._folders = [f.split('    "')[(-1)].strip('    "') for f in response]
        self._folders = [(_basename(f), MailFolder(self, f)) for f in self._folders]
        self._folders = [(f, o) for (f, o) in self._folders if (f != '')]
        self._folders = dict(self._folders)
    return self._folders
