This article describes an email project carried out jointly by the Institute of Modern Languages and the Department of Applied Languages at Antonio de Nebrija University in Madrid and the University of Massachusetts Amherst (UMass) in the US during the first semester of the academic year 2004-2005. Students worked with a partner exchanging personal, linguistic and sociocultural information and corrections about each other's language (English and Spanish), as well as taking part in a discussion forum. The project generated a wealth of data which raised some interesting points and the information gathered from one particularly successful partnership is presented. However, further research needs to be carried out on how best to assess the improvement of the students' language proficiency through the use of email tandem learning.