If a service is not working and resetting it to defaults is not working and you get bizarre error messages it is probably a broken update and possibly duplicate package.
Take in this case "exim" not working even after resetting to defaults.
Check for duplicates:
rpm -aq|grep exim
........
CPanel says you can access 98% of the functions through CLI which experienced Unix/Linux admins prefer for simplicity and for scripting. I've never found CPanel easy to use from the admin panel, it seems everything is hard to find and a simple task becomes a series of hunts.
So for people like me here's the list: http://cpanel.net/system-administrators/command-line-scrip........