My email is an organizational disaster. No lie. I also made my situation worse when I decided to consolidate several accounts. Gmail decided to bring over years worth of old email even though I only wanted those that were currently unread. I'm sure there was some kind of setting that I missed.
When I saw thousands of emails staring at me, I knew I needed to do something to mitigate this mess. Surely, there must be a faster method than slogging through them one at a time. I Googled.
I saw all kinds of organizational systems. From one guy saying you should never have more than five email folders (NO!) to another advocating breaking everything down into folders. I saw claims that folders didn't help anyone locate email and that search is faster. Someone else talked about giving emails very distinct, targeted titles. Which absolutely doesn't help since a lot of this email came from other people.
After all of my searching, I found nothing that gave me ideas on how to slog through my mess.
I made a few shortcuts of my own. When I found your item has shipped emails for things I've received (and since some of these emails are ten years old or more, they were most definitely received), I auto deleted them. Loop emails that were years old are gone. I figure any writing advice from ten years ago is obsolete by now. I found other things like this to speed things up.
After hours of work, things are better, but there's still a long way to go. I figure now, I go folder by folder and try to think of ways to shortcut that one particular label if I can, then move on to the next.
I'm estimating that my method will lead to an organized and efficient email collection by about 2057.