King Mustard said:
It's a work e-mail account, on a work PC, on a work network; I have no idea which ISP they use etc.

I usually just enter the e-mail address and password and it starts working.
Hi there
@King Mustard

If it's a work one then it should work 100% -- I'm not sure how your work I.T dept works but I'd just create a ticket and submit it. You'll probably have the problem fixed within the hour as email is usually important within a business. When you start outlook from a works computer for the first time (at least in my experience and I've been at hundreds of clients over the years) it usually automatically configures.