Google Postmaster

Google Postmaster Tools helps newsletter operators monitor the health of their email sending to Gmail users. It provides insights into how Google perceives your outgoing email, which is crucial for maintaining deliverability.

This tool offers dashboards with detailed information on your spam rate, domain reputation, IP reputation, message authentication (SPF, DKIM, DMARC), and delivery errors. Understanding these metrics allows you to identify and address issues that might impact your newsletter's inbox placement.

By tracking these indicators, you can ensure your email practices align with Gmail's sending requirements. This helps prevent your newsletters from being marked as spam or experiencing delivery delays to personal Gmail accounts.

To use it, you add your sending domain and verify it, typically using DKIM or SPF records. The data specifically covers messages sent to @gmail.com or @googlemail.com addresses.