“To set up the Gmail Postmaster Tools, you have to add a CNAME or TXT DNS record. Google will then test these records on a recurring basis to verify ownership.”
In addition to using your ESP’s analytic tools, you should also try using Gmail’s new Postmaster Tools, released during the summer of 2015. Postmaster gives email marketers the advantage of reviewing performance and trends from a new vantage point. Learn more about bounce rates, unsubscribes, and non-deliverables in one easy-to-use dashboard.
