Can anyone recommend a good Windows-platform email client? I don't really want to buy Outlook and Outlook Express is kinda rubbish

Meh, Thunderbird is disappointingly rubbish. Eudora has its moments, I guess. There's quite a good review page here, but it puts Thunderbird at the top.

That said, I mean, I hate to say it but Outlook is the most fully-featured you can get, really. The multiple address book support and calendar features are really useful. You might have to bite the bullet...

I use Thunderbird and I don't have any problems with it, but then I'm not trying to do anything very exciting. The RSS support is good.