Google's conventional e-mail client for Android has always felt like a second-class citizen compared to the company's GMail application. It has a very limited user interface, lacks basic features like support for moving messages between folders, and isn't particularly reliable. Google has been slow to address the program's weaknesses and doesn't seem to notice most of the complaints.
Fortunately, there is a good third-party fork called K-9. It's not particularly pretty, but it's highly functional and well-maintained. K-9 is based on Google's original Android mail client and is similarly distributed under the open source Apache license, but it's got a whole pile of additional features.