I don't think that it is quite a joke. it just seems to be somewhat lacking in features. It is a matter of just taking a look in mail clients of other phones and implementing at least the basic features. Then, take all the brainstorms and "wontfix" and "moved" filed bugs and take a look at them.

On the other hand, maybe it is so complex that anohter email client would be really the choice. I wonder if Thunderbird is to heavy to run on Nokia N900, though.