Setting up a Site Server with Jaguar
Subject:   Make sure to install the BSD Development headers!
Date:   2002-09-11 13:58:43
From:   duncan
Response to: Trouble compiling imap

You need to be careful about installing the BSD development headers when installing the development tools. Since you didn't, you are seeing the error you see here. Go back and reinstall the dev tools and you'll be fine.