Open rates and clickthrough rates are the most common benchmarks people use when talking about email marketing success. An open rate is the percentage of people who opened your email from the total that received it. Your clickthrough rate is the percentage of people who clicked on a link in your email from the total number of people that opened it. These two metrics are the ones most people think of when measuring their email marketing, but they aren't the only ones you should focus on.

Other metrics to track depend on the goals of your email sends. Are you trying to generate leads? Get someone to sign up for a demo? Get someone to buy your product? You should figure out how you can measure email's impact on those numbers.