It seems to me that one of the biggest drawbacks to a web-based client is the inability to click a mailto link in a web page or use the Windows "Send to: email recipient" feature. The toaster app is a great move in that direction, with notifications of new mail. Now if the developers could add the outbound functionality and have it default to toaster when one of the above actions is performed by a user, I can't see why anyone would object to the AJAX client. It's WAAAAYYYYY nicer than Outlook! But users are gonna hate giving that up.