In my experience, they're usually far more customizable. Clients I've used include KMail on Linux, The Bat! on Windows and Mozilla's Thunderbird, all of which o

In my experience, they're usually far more customizable. Clients I've used include KMail on Linux, The Bat! on Windows and Mozilla's Thunderbird, all of which offer myriad options to customize the appearance and behavior of message list, message pane and folder lists, though the first two apps much more so than Thunderbird. You also get to modify things like toolbars much more freely, and OS/toolkit theming usually also beats the GMail theming system. You could argue that GMail has a higher customization potential given the fact that you can muck around with the document client-side (though Thunderbird extensions are similar, and if you really go down that road: I can also change the source code of KMail and recompile it), but we're talking in-app options here. And so I find the notion that "GMail has impressive configurability because it has the options described in the article" amusing. Somehow the world has forgotten just how sophisticated an experience a regular old desktop app running in the context of a regular old desktop environment can be. I'd also argue that regular old desktop toolkits and libraries still require a lot less investment of effort to achieve such levels of sophistication than the web development environment does at the moment. Like I said, thought-provoking.