How would such a webmail be integrated with OpenACS? Would the emails be full-text searchable? I suppose one obvious but small advantage would be that you would have immediate access to all the email addresses of all the users on the site.
On the other hand, we have always encouraged using discussion forums rather than email for correspondance that can be of general interest. It happens very often that I see email exchanges that should really be in the Bboards. We need to be wary to not overuse email.
I rely on Fastmail.fm for email. FastMail.fm is the ultimate Hotmail killer. It is easily the best email service that I have seen (has POP and IMAP, virus and spam protection and loads of other features) and an extremely efficient and usable webmail interface. Fastmail also has a very active Discussion Forum of users and developers. In fact, Fastmail is so good that I wonder why anyone would go to the trouble of hosting their own webmail, unless there are some significant integration benefits that I don't know of.
