Like you, I've tried lots of different mail apps - Mailbox, Sparrow, Airmail. I've enjoyed using Thunderbird, Outlook, Mail. And I've used web interfaces for Gmail, Fastmail, Hotmail, etc.<p>In the end, which email client I've used has barely made any difference. The key is in processing the emails - forwarding to Evernote for reference, adding to Omnifocus if it's a todo item, replying quickly if I can, or deleting if it's irrelevant.<p>I found that extra features like tags and snooze just made me more disorganised, instead of less, as I spent more time fiddling with the features and wondering why something had gone wrong.