Measuring trust among social network users is an important research issue. In this paper, we present a new trust model based on emails. We name this new trust model as Email Trust (EMT). EMT is constructed based on the interactions among users via their daily emails, which provides a level of belief on the data transmitted by a use. In EMT, we require each user to perform a trust checking procedure and process a received trust checking request from their highly trusted email contacts or through a trusted checking proxy server that is maintained by a trusted third party. We evaluate the EMT through a small EMT testing bed developed using Gmail services. Our preliminary evaluation results show that the EMT evaluation results can be used to represent users' trust among email users.