Using the Internet today, both end-users and automated systems rely on the Domain Name System (DNS) to translate human-readable domain names to IP addresses for communication between machines. This system from 1985 has only in recent years seen Internet standards addressing security and privacy concerns. In the position as a machine-in-the-middle between the client and the distributed hierachical system of authoritative name servers, we find the DNS resolver. Due to its purpose of forwarding, looking up, and caching queries and responses, in addition to its location between the clients and the name servers, the DNS resolver becomes a critical point for implementing these security and privacy features. The widespread adoption of these features, their variation in implementation, and impact on both clients and other name servers remain as interesting topics in the research community. The goal of this thesis is to analyze servers in the wild and conduct a comprehensive investigation into the security and privacy mechanisms configured on DNS resolvers. Using an Internet measurement approach, we explore the trends in the adoption and implementation of these features by generating and observing our own queries to and from the resolvers. We also investigate how clients and the DNS ecosystem as a whole are impacted by resolver configurations. We use and improve methods for measuring adoption of various security and privacy related features. Based on these measurements we report the current level of adoption and adoption over time, investigate anomalies, and identify limitations with measurement approaches. We fingerprint the software and version of popular open-source DNS resolvers by classifying query patterns. Comparing the ingress and egress resolvers we analyze forwarding behaviors and their impact on the availability and effectiveness of security and privacy features. We also cross-analyze features in DNS resolvers to find correlations, which could help us understand obstacles and find solutions to feature adoption.