This pretty much filters all non-important emails. It's amazing.

https://xph.us/2013/01/22/inbox-zero-for-life.html

Your one and only goal for processing your inbox is to make it empty. Not to actually do anything productive, because processing email is inherently anti-productive. Don’t fool yourself into thinking you’re doing work here. Just get it over with as quickly as possible.

> "This topic of productivity induces the worst kind of procrastination, because it feels like you’re doing work, but I was producing stuff that had the express purpose of saying to people, ‘Look, come and see how to do your work, rather than doing your work!’"

The point being, I'm only to do this once a month. I have a few other similar ones, where I was procrastinating with tasks, but now only do them once per period.

I haven't actually watched Mann's talks and only have a second-hand understanding of Inbox Zero as a concept, so maybe this is just rehashing his ideas, but the reason I like this approach is that I avoid spending the time and mental effort classifying incoming messages more than once.