In this video I show you how I configured my Gmail account to automatically delete unarchived mail after 7 days that hasn't been starred or marked as important. I set this up for free using Google's own Apps Script service which allows you to write scripts that interact with Gmail using basic JavaScript.
A detailed blog post with more information can be found at https://benbjurstrom.com/purge-email
The source code used in the video can be found at https://gist.github.com/benbjurstrom/...