> over 100k emails to go through in one lifetime isn't worth the trouble

Unless you're on a bunch of mailing lists, I can't even fathom having that much email, much less that much unread email. I'm fanatical about making sure that I'm at inbox zero as much as possible because the 'unread' counter is the enemy. It takes some effort to set up and adjust filters and actually unsubscribe from stuff, but it's completely worth it to have a mailbox that's actually usable.