Distance learning is expanding rapidly in universities. While theoretical and qualitative literature stress the critical role of effective interpersonal interactions in motivating students and facilitating learning in online environments, quantitative evidence on the benefits of increased interpersonal interactions on student learning outcomes is limited. This study examines the effect of providing a voluntary in-person meeting time in a physical classroom and increasing instructor email activity in a fully online precalculus course at a public university. We examine student final exam score and course grade as outcome variables. Student selection into courses was minimal since students only had access to one treatment condition at a time. We further used a propensity score matching strategy to address demographic variations in student characteristics across cohorts. Our results indicate that the increased interpersonal interaction opportunities increased final exam scores by 0.22 standard deviations and improved passing rates by 19 percentage points. Rosenbaum's sensitivity analysis indicates that it is unlikely that these results are due to omitted variable bias.