This paper examines the effectiveness of providing personalised email feedback via an automated email application in a large undergraduate introductory accounting course. Over 1,200 students received feedback via emails sent weekly, semi-tailored to each student based on their results in online self-test learning quizzes. We first found that students read the majority of emails distributed. Second, through tracking, using regression analysis, we found that reading emails is related to significantly higher final examination performance in some cases. However, this is moderated by factors relating to diversity in a large cohort exceeding 1,000 students. The results indicate that feedback needs to be readily actionable and aligned with assessed learning outcomes to realise significant impacts on exam performance. This study is relevant to educators who teach large and diverse cohorts and need time-efficient solutions to tailor the learning experience to each student.