SentSonar — Accurate Email Open Tracking

SentSonar tells you when someone actually read the email you sent from Gmail — and, just as importantly, when nobody did and a machine merely fetched your tracking pixel. Every open tracker sees the same raw signal: a request for an invisible image. Most tools count all of them, which is why you get a "read" the second you hit Send. Gmail caches remote images at delivery, corporate gateways scan links, and Apple relays prefetch on the reader's behalf. SentSonar classifies each fetch — timing, burst pattern, network operator, user agent — and only calls it a human open when it looks like one. WHAT YOU SEE • A badge on every message in your Sent list, All Mail, and inside the conversation: ◦ Tracked — sent and being watched, no opens yet ◦ Read — a human opened it ◦ Machine — fetched by a proxy or security scanner only ◦ Degraded — the pixel could not be tracked reliably • Hover any badge for the full open history: how many views, how long ago, the time of each one, the network the open came from, and an approximate location • Relayed opens are labelled as what they are — "via Gmail image proxy", "via a security scanner" — because that location is the relay's datacenter, not the reader's town • Unlimited history. Scroll back to mail you sent years ago and the badges are there • An optional desktop notification the moment something is read (off until you turn it on) NO ACCOUNT, NO LOGIN There is nothing to sign up for. Install it and your next send is tracked. Reinstall the extension, or set up a new computer, and your history comes back on its own — your Sent list repaints itself within seconds of opening Gmail, with no reload and no sign-in. WHAT WE DO NOT COLLECT • No subjects. No message bodies. No recipient addresses. None of it reaches our servers • Your Gmail address is never sent — history is keyed to a one-way hash of it • Your own views of your own Sent mail are suppressed, so you cannot trigger your own "read" • An opener's IP address is used to classify the open and to derive an approximate location. The extension only ever shows you a truncated network prefix (e.g. 203.0.113.0/24), never a full address • Notifications, and the push subscription behind them, exist only if you enable them Privacy policy: https://sentsonar.com/privacy/ Terms: https://sentsonar.com/terms/ KNOWN LIMITS, STATED PLAINLY • If a recipient blocks remote images, there is nothing to detect and never will be, by any tracker • A Gmail tab that was already open when you install needs to be reopened once • Locations are approximate, and for relayed opens they describe the relay, not the reader