I've been pottering about some ideas I have for making my mail systems work better together and one of the areas I've been looking at is WebMail applications.
Why is it that so many of them use IMAP as the source of the mail they allow you to access? It seems pointless as the whole idea of IMAP is to provide remote access to your E-Mail. If you have a mail client which can read mail using IMAP then you don't need WebMail at all do you? Apart from anything else WebMail tends to be slower and is an unfamiliar interface. Some E-Mail clients even handle POP3 mailboxes 'remotely' quite successfully. (I think it's either xfmail or xcmail that does this)
It would make much more sense if WebMail applications allowed you to access mailboxes that *aren't* normally readable remotely.
I suppose that a WebMail application means it's easier to access your mail from somewhere that doesn't have your own MUA but that's about all it does.
What I'd find really useful is a WebMail application that will let me read a tree of mbox mailboxes on a remote server.