Personal mail I use default mail app. Works well enough for me.
For work I use an application that ties into the work's exhange system (as we do not allow active sync to support generic 3rd party...some 3rd party can work around this ofc, its what 3rd party does to make money lol). Its called good, but imo they thought too highly of themselves giving themselves that name. I tbh only use this app when clients I support say the system (its an added server to the exchange environment) seems to be not working.