On Android 5 the normal mail client got hijacked by the Gmail app. I still want a standalone mail app. Currently I try Blue Mail + K-9 Mail. So far I find them rather similar, and not too different from the android house mail app. Blue Mail feels a little better, but K-9 is open source, which I generally prefer. But I haven't really explored all functions yet. I wonder what are your thoughts about it. Opinions?