The native Mail app lacks (at least for Android 2.1) basic features like move a message to another folder.
What alternative apps do you recommend?
I used TouchDown (30-day trial, $19.99) before Android had built in Exchange and was very happy with it. I'm now using the native client without many problems (I'm not very demanding of it), but I've heard many people mention that it is still worth buying over the native client because of the more advanced feature set. With the 30-day trial, no reason not to give it a try.