domain security
GPT — Google Postmaster Tools (or Gmail Postmaster Tools) is a truly handy thing for email senders, especially email marketers who need data and deliverability monitoring. It is a reputation dashboard that pulls together IP address reputation, domain reputation, bounce and complaint metrics, and more, all in one handy interface. GPT is domain-based, meaning that you configure it to provide you data on either your return-path or visible from domain, authenticated by way of SPF and DKIM. You tell GPT which domains you want to monitor, and you then prove that you own or have admin access to each given domain by implementing a key string in a TXT record to demonstrate that ownership. Deliverability consultants and marketing managers can use the data to great success — showing proof that whatever changes (strategic, technical, segmentation, etc.) made to a marketing program are showing improvement as measured by the good/bad reputation