Thanks for all your suggestions - this is a great site.
I'll certainly check with my work again to see if the problem is on their end. I work for a university and their IT support is pretty much non-existent, especially if you are using things like email from outside their network - but I'll give it a go. What I can't understand is that I can access my email from a dial-up account using the same settings as I use when connected via BB. Excuse the newbie ignorance, but could they have blocked access to the email servers from specific IP addresses?