The problem being that Outlook on my MBA/El Capitan keeps giving me the "invalid username/password" error and won't let me even compose, let alone send and receive - though the username/passwords/configurations are all correct, quadruple-checked (more than that actually), and verified with my ISP (TWC), and are actually the same accounts that are functioning flawlessly on my iMac/Snow Leopard with the same Office.

So would an uninstall-reinstall fix that? If so, should it be the simple one, dragging the Office folder to the trash? Or the full uninstall?

Thanks all.