This paper tests for racial discrimination in the rental housing market using matched pair audits conducted via e-mail for rental units advertised on-line. We reveal home-seekers’ race to landlords by sending e-mails from names with a high likelihood of association with either whites or African Americans. Generally, discrimination occurs against African American names; however, when the content of the e-mail messages insinuates home-seekers with high social class, discrimination is non-existent. Racial discrimination is more severe in neighborhoods that are near “tipping points” in racial composition, and for units that are part of a larger building.