Zonmaster is an Amazon management tool that handles email dispatch, management, and analysis for sellers. It provides insights on email metrics, orders shipped, and reviews received. Features include a custom dashboard for sales management, email automation for autoresponder templates, automated review requests, and pre-sales landing pages for email collection and coupon distribution. It also offers feedback management for personalized emails and campaigns, and monitors Amazon ASINs for changes like reviews, pricing shifts, and hijacker activity.