If you have several IMAP accounts on your mail server that you can access with mail app on my Droid. Each has a number of folders for filtering/saving mail in. While you can access folders but you cant move messages between folders.
So you should check into "K-9" App as it has the ability to move messages to another folder and but one drawback is there is no multiple select option or archive option for gmail. Few users have reported about K9 that every time it checks email it shows everything as unread by showing headers bold (new) every time. Can click on them and it will make the headers return to normal font, but when K9 checks the mail again it makes the headers bold again.
You may want to check the issues list and/or post your problem on the k-9 site also.
http://code.google.com/p/k9mail/issues/list
You can also consider "seven." but it passes all your emails through their servers and on seven's website can't review features or view the release notes to determine if, in fact, the Droid is supported without registering first.
