After trying different email clients (Sparrow, Mailbox, Airmail, etc) just to see most of them getting abandoned, I&#x27;ve decided to simply stick to the native email clients provided by OS X and iOS and use fastmail.com with a custom domain name. Fastmail is about as flexible as it can get, their IMAP support for OS X mail.app is fantastic and their push notification service is actually better than Apple&#x27;s (Fastmail pushes &#x27;new&#x2F;read&#x2F;unread&#x2F;delete&#x27; notifications, whereas Apple only pushes &#x27;new&#x27;.