As mentioned in passing in the second post in this series I have a lot of email accounts, and over time they've all ended up hosted by google.
You'd think the default Android email app would be great then, or the gmail app would be good on Android, but for a couple reasons I believe they suck. The main reason is that they don't provide a unified inbox for all your accounts on a single screen. I had no idea this was a thing, having gotten used to the built-in iphone mail app, but apparently it is. And the default clients just don't get it. I'm not going to get one new mail in each of 5 clients and spend a lot of time thumbing into and out of the various inboxes - that's my main use case and it's horribly inefficient. Unified inbox is non-negotiable.
Search around the internets and you see lots of reference to K-9, but apparently that app has gone rogue with offshoots from old forks, a new "Kaiten" version, and updates to the K-9 app itself which apparently suck. So I stayed clear, but it may work for you.
The one I finally went with was MailDroid. Configured it up pretty easily (or as easily as it can be when you have all 5 of your google accounts configured for 2-factor authentication and you have to generate application-specific passwords, which you do so your account isn't easily attacked, right?), et voila, pretty configurable control over how each account works (using server folders where desired, how many mails to load etc) and a unified inbox.
MailDroid gets bonus points for allowing me to shrink fonts for real to get more info on the screen, for allowing me to indulge my college-days hacker self with a reverse video theme, and for allowing me to easily set a global signature and global connection settings.
Have you discovered a client better than MailDroid? Any tips or tricks if you are using MailDroid?