I suspect that this is just a design flaw because everyone at Google uses GMail. I'm one of those old-fashioned people who actually likes to file his email into his folders (and sub-folders) on his Blackberry.
I just picked up a Sprint HTC EVO (4G) running Android 2.1. To file an email after I read it, I need to go back OUT of the email to the Inbox, click Menu, then More, then "Move." Then RESELECT the email I want to Move... And picking the folder to move to is even worse: the Android UI doesn't give me a nice control to expand and contract my list of email folders and subfolders (like the Blackberry does, as does Outlook on my PC)--it's lists all 40+ of my folders and subfolders in one giant list.
This is totally unusable. So sad it's so poorly done and driving me back to my Blackberry. Is Android ever going to acknowledge that some of us use email other than GMail and support Moving emails to Folders more cleanly???
joel