Sorry, I dont have much experience with tracking emails. Usually tracking of email is done via tracking pixel (its an image of size 1x1 px. When the recipient opens the email, their email client makes a request to the server hosting the image, and this request is logged, allowing the sender to track email opens.) Read more at https://www.nutshell.com/blog/email-tracking-pixels-101-how-do-tracking-pixels-work Are you planning to get a global analytics or need to uniquely identify the email address to see whether they have opened the email? First one is easy, you can insert that tracking pixel code in the above program. The later is difficult. (Would be a nice project though). There is a tradeoff, if the user is using skiff mail with remote content turned off or using duckduckgo email forwarding, such pixels wont be loaded or is stripped off. If your project is not so focussed on email sending, it would be easier to use sendgrid, mailchimp etc.. for the analytics. I will definitely do more research on this and will let you know if something comes up.