
Likelyread shows which of your emails were opened.
A tracked email carries a 1x1 image (the pixel) at the end of its HTML part. When the recipient's mail app loads it, Likelyread records a hit and classifies it as an open, a view of your own, or a privacy prefetch.
https://app.likelyread.com/mcpNone in the store listings. The server needs sign-in, so we could not check it