How I (try to) Achieve Email Zen

I'm continually on the lookout for ways to make life inside my inbox a little more pleasant, peaceful, and efficient.

Here are the tools and systems that are working for me currently:

• Gmail: I have all three of my email addresses feeding into one single mailbox. I use the forwarding and "send/receive as" functionality.
• "Send and archive" feature in Gmail: saves lots of time and lots of clicks. 
• Unroll.me: to roll up many of my subscriptions into a single daily email (though my subscriptions are still a bit out of control)
• Insightly: I use this as my CRM, and I use the Gmail plug-in. The plugin is okay but not great, as it doesn't always recognize new versus existing contacts. (I previously used Streak for Gmail but switched about a year ago when I needed something a bit more robust.) 
• Sortd: I just starting to play around with this - a way to move emails to different lists (ie: follow-up, tasks). Appeals to my visual side, and still feels a little freaky and rebellious to me.
• I use batching/Pomodoro as much as possible to work my inbox during set blocks of time (instead of checking it throughout the day). I typically try to do it in 30-minute chunks mid-morning, mid-afternoon, and sometimes in the evening. 
• Joe and I use Asana to communicate about tasks, projects, and questions that arise between our in-person meetings. We don't really use email at all to communicate between the two of us.  

What about you? What are your favorite ways to achieve (or work toward) Email Zen?