How do I download messages to another computer once I've enabled POP?

You can download your Gmail messages to another computer at any time.* To download messages you received before enabling POP, just follow these steps:
  1. Sign in to Gmail.
  2. Click the gear in the top right.
  3. Select Settings.
  4. Click Forwarding and POP/IMAP.
  5. Select Enable POP for all mail.
  6. Choose the action you'd like your Gmail messages to take after they are accessed with POP.
  7. Click Save Changes.
  8. Configure your POP client.
* All messages may be downloaded to another computer once; after downloading mail, it will not download again.