I've found the mail app from Zoho to be very good (assuming you have your own domain). It's obviously not perfect, and there are always pros/cons when switching

I've found the mail app from Zoho to be very good (assuming you have your own domain). It's obviously not perfect, and there are always pros/cons when switching between apps. I found it relatively quick to setup and get working. And compared to Google-apps for business, it is free for X amount of users per domain. Not affiliated to them in any way, just thought I'd share what I've been using recently alongside my main gmail user account.