So, the mystery as to why my Outlook refuses to let me access the inbox continues...but it's a mystery I can live with. I took speakr2customrs's advice and installed Thunderbird instead, and so far, it seems to be working fine. The proof of the pudding will be in the eating, i.e. logging off and trying to get back in again in a couple of hours, but for the moment, I'm basking in the knowledge that I'm once again connected to my mailserver. So thank you, Speaker!
ETA: the weather's atrocious - rain, sleet and hail all at once - and I just saw a green and yellow parakeet fly by my window! Must have escaped from somewhere...can it survive out there? Should I go out and try to catch it, bring it back into the warmth?