How do I stop Pine from downloading messages to a local mbox in my home directory?
If there is no mbox file in your home directory, then Pine will not download messages to your local mailbox. If you want to disable it at compile-time, you should build Pine without “mbox” being listed in the EXTRADRIVERS option. You may need to do this if you have users that are using other MUAs that create an mbox file, along with Pine. There was a recent thread on this on comp.mail.pine. Please read it here, especially Message #5 from Eduardo Chappa if you are having problems.