mbox mails with Thunderbird-3.01

  • Hi,
    sorry, I couldn't find any help using Google.
    My mails are managed by a local MTA (postfix on Linux) which stores all mails
    into a single file (mbox format).
    How can I set up a mail account reading emails from this mbox file. Thunderbird always
    assumes an IMAP server. How can I change this?
    Many thanks for a hint,
    Helmut.