Tracking user engagement involves using various tools and techniques: 1. Email Marketing Platforms: Tools like Mailchimp, Constant Contact, and HubSpot provide built-in analytics for tracking metrics like open rates and click-through rates. 2. UTM Parameters: Adding UTM parameters to your email links can help you track the performance of your campaigns in Google Analytics. 3. A/B Testing: By testing different elements of your emails, such as subject lines or images, you can determine what works best for your audience. 4. Heat Maps: Tools like Crazy Egg can provide visual representations of where users click within your emails.