I finally got so damn annoyed at IMAP clients two days ago that I started writing my own using the JavaMail and SWT as a frontend (so it will actually be snappy). I had been using Outlook Express (which disgusts me). I'll let you guys know when I get it basically working. Right now I'm using the IE renderer from inside of SWT to display the messages, but I believe they have wrappers for Gecko too, so it should work on non-Windows pretty decently .... I'm actually modelling the app a lot after Mail on OS X (like the way they do colored/layer replies and grouped folders, like a single INBOX that you can view all of your INBOXes together in open the node and view each account separately).