This will be brief.
Inbox zero is a valuable thing to maintain. Roughly promoted around the web as having an empty inbox.
An email inbox collects a few things:
- junk
- automatic mail sent to you
- personal mail sent to you
- work sent to you
- (maybe - work you send to yourself because that's the best way to store information for now)
- Old as all hell (or other friendly name)
- 2014
- 2015
- 2016
I do not believe the intention of the advice given is that emails in your inbox that you feel require some reponse, but that you don't see how to deal with completely in a few minutes, should be archived and forgotten. (Perhaps I misunderstood?)
Don't know, not the original author. What do you think the chances are than an email on the third page of your inbox will ever get a reply? Inbox purgatory seems to me like a way to give up on something without having to admit it yourself.
If my inbox has more than 40 or 50 items in it I feel demoralized and find it harder to work through newer items, so the easiest way for me to stay at steady-state is to keep my inbox at zero or close to it.
Counterpoint: I've kept to an empty inbox for many years, but know people with ever-growing inboxes whom I consider more organized and responsive. I've never declared email bankruptcy during my professional life and don't know the consequences.