Is it possible to detect whether the customer has opened the email_html/css_WEB-ITnose

html email database HTML email

I insert something into the html code of the email and link it to my website database
Then I look at the database to know how many people have opened the email.

How to make something like this? Is it feasible?

Reply to discussion (solution)

Works.
Insert an image into html, and the image address is an absolute external address. For example, xxx.com/counter.gif?id=unique identifier (or .php .jsp .aspx .asp) will do. Make sure that the external address first performs query and statistics (that is, based on the id), and then returns a transparent mime type of A 1*1 picture of gif is enough.
Or you can use a linked style sheet, the principle is the same