Well, Sussex University email is hopelessly (yes, hopelessly) broken this weekend, so now seems a good time to switch to a proper email provider for my primary account.
Gmail seems to be the best of the bunch by far, offering IMAP and an excellent webmail interface, free of charge. (Yahoo won't give you IMAP access, and Hotmail ... enough said!) I'm using Apple Mail on the Mac, and setup was easy, thanks to some helpful instructions on Geekology (I didn't use the "IMAP Path Prefix" bit though). A few very minor issues (such as the way many messages appear twice or several times when you seach in "All Mailboxes"), but I'm very happy so far. Except that I still have 191 messages waiting to be dealt with, plus however many are sitting in a queue (I hope!) at Sussex...