Using New Outlook on Windows for personal email, calendar, and contact management
I have used Postbox for years. It has had it's fair share of problems and the last problem (read messages remain marked as unread and you have to manually mark every message as read) made me look at the new Outlook again.
But: STILL NO UNIFIED INBOX.........
And the conditional formatting rule is not supported for accounts other than MS. (Oh, let's just use our power to bully people into using MS accounts only)
Mickeysoft is doing a great job in alienating people.