As I understand it, one of the primary reasons Google removed the IP reputation graph from Postmaster Tools is that it exposed too much visibility into the underlying mail infrastructure. Regular users of the platform could assess the health of the ESPs and CRMs distributing their mail.

At my company, we relied heavily on that data to evaluate the reputation of IP addresses our clients’ traffic was routed through. This insight allowed us to advise clients when they needed to move away from underperforming platforms or CRMs in order to improve deliverability and compliance.

I believe that level of transparency was a significant concern for Google, which is why the graph was ultimately pulled from public access.

I expect this change opens the door for low-quality platforms to be abused by spammers while still claiming their infrastructure is healthy, with no independent way to verify those claims.