I'm a bit extreme when it comes to my email. Work insists on outlook so I use it there, but for private email I forgo dedicated software. I use webmail on my phone (husmail.com). It is slower, but when the airport security guy asks me to "unlock my phone" I can do so without revealing my email conversations. I don't trust my Andriod phone in the same way I do my ubuntu/mint/kali linux machines.