Sender Score

Sender Score is a free reputation lookup tool built by Validity that rates your IP on a 0-100 scale based on mail stream data from over 80 mailbox providers, ISPs, and corporate networks. Check your sending IP to see how Gmail, Outlook, Yahoo, and others perceive your reputation. The tool also flags spikes in complaints, bounces, and authentication failures that might harm your inbox placement.

Marketers sending from shared IPs use this as a quick diagnostic when they spot a sudden drop in deliverability, since the score updates several times daily. If you're evaluating a new email service or switching sending infrastructure, run your IP through Sender Score first to catch problems before they hit your open rates. It's most useful alongside your ESP's own postmaster or feedback loop tools.