Finally, why does Outlook suck?
Outlook is - and always has been - designed first and foremost as a client for Microsoft Exchange.
It actually works very well in that environment. It also woakrs reasonably well as a standlone POP client, but its IMAP support has always been lees than happy-making.
I'll be *really* happy when the Mozilla Sunbird Project is mature, and Lightning is a full featured, fully functional Calendar extension for Thunderbird.
-- Best regards, Charles