I think what you’re looking for is called a Web Beacon or tracking pixel.
A tracking pixel is just a small transparent image embedded in the emails you send out. When your recipients open the email, their client (Gmail, Outlook, etc.) will send a request to download the image. This works the same way that your web browser downloads this cat image. Instead of a cat, you should use a small transparent image though.
You can link the image to your server, like this:
<img src="https://your-server.com/email-tracking/USER_TOKEN">
Then, on the server side, you could create a resource that would handle these requests. When you receive a GET
request for /email-tracking/USER_TOKEN
you could increment the number of times the user with that token has looked at your email.
You should note that this won’t always work. If your recipient has turned off images in emails, or turned off HTML in emails altogether, then their client won’t send a request.
solved how can I do to know how many times the recipient open the email or the number of click? [closed]