Social and societal exclusion, which were constitutive for National Socialism, were accomplished not only in public media but also in field post letters. Writing letters was a fundamental everyday media practice and the field post was a central social medium during the Second World War. Applying the concepts of agency and dispositif to the field post, this paper analyses both infrastructural and interactive practices of exclusion. The article identifies different practices of excluding agency and shows how exclusion was carried out through discursive practices in private communication under the discourse conditions of National Socialism.