Email declutter

I have in excess of 10,000 unread emails from various subscriptions, delivery notifications and general junk mail across four email accounts. It reminds of the Tetris game where the blocks keep coming down and you lose the game when it reaches to the top. It’s exhausting having to sift through them on a daily basis to identify the important purchase or credit card notifications and school related mails. How do you deal with the volume of mail? To make matters worse, important emails frequently end up in the spam/junk folders and so I have to trawl through these folders as well to move them back to the main inbox. Go figure! An hour a day is easily taken up in this daily battle. In contrast, my work emails are diligently monitored, filed or marked for further action almost with military precision, with an average of 50 emails in my inbox by the end of the day. I am able to retrieve related topic emails to as far back as 2005! Does this boil down to the important learning of what matters most counts?