I've been using Outlook for iOS for over a week and really like it. Outlook 2016 ( version 15 ) for Mac was clunky so I went back to Apple stock mail app. However I started a new Office 365 subscription I have Outlook version 16 . It runs like a dream and works well with my hosted MS Exchange email. I really like the interface of both apps, but the email features roped me in. Mail sweep for easily finding and take action on a batch of emails, mail retention policies that can be applied globally or to individual folders.
I use retention policies to clean up deal / sale emails as sales usually are done in 30 days, so I have them delete email older than that automatically.
Server side rules - it's really easy to write complex server side rules that run whether or not your devices are online.
This set up does cost you a subscription fee, but it saves you a lot of time managing email. For me the time savings are worth the price.
I check Outlook for Mac every once in a while and am frustrated by the fact that, unlike Outlook for Windows, the list of “Conversations” still doesn’t include one’s own sent emails; you still have to view those in the Reading Pane. It’s not as if I expect total feature parity between Windows and Mac versions, but that difference is particularly galling, especially in long, drawn-out threads (“Conversations”).