Hello, I'm wondering if it's possible to code email campaign tracking (open rates, read rates, etc.) without using any third party tools/services - only by coding? If so, any resources that explain how?

The same question goes for UTM tracking, i.e. tracking rates for link clicks. Do I need to use tools for this as well?

I'm asking as since I work in a government environment and here they're quite sensitive to not using third party applications.