When you send an email to your subscriber's list, it's often to bring them back to your website or product. But how can you tell that one website visitor is coming from this specific email?
Well the solution is to apply a specific tracking system to each URL in this email. 2 ways are
Auto-Tagging vs manual tagging
Auto-tagging from your email service provider (ESP)
Your email service provider should have an option to automatically track link clicks and can apply a specific criteria to your url.
To know that one subscriber came from one specific email, you could check that specific criteria in Google Analytics for example.
Manual tagging in your link balise
Similarly, you can do this manually by applying UTM parameters to your URL.
For example, instead of linking to only https://emailtech.co/ you can link to https://emailtech.co/?utm_source=newsletter&utm_medium=banner&utm_campaign=black-friday&utm_term=20PERCENTOFF
See the official builder and recommendations from Google to make the best use of the UTM parameters. Here is the official UTM builder.