Postbox contact, in which an adoption agency mediates the exchange of letters between adoptive and birth families, now appears to be the most common contact plan for adopted children. Despite their prevalence, postbox services have received little attention from researchers and is not the subject of any national policy or practice guidance. This article by Julie Selwyn, Lesley Frazer and Peter Wrighton draws on a recent evaluation of one local authority's postbox service and in particular the perspectives of adopters, birth mothers and extended birth family members using it. The evaluation found that adopters and extended family members were often very committed to sustaining the service for the benefit of children. However, birth fathers were rarely involved and birth mothers had great difficulty in writing, although they valued receiving news of their children. There was considerable scope for disappointment when parties embarked on postbox with different expectations and could not directly communicate their motives and wishes. Overall, the paper concludes that postbox users require more support if this form of contact is to be sustained. It also calls for researchers, practitioners and policy makers to devote further attention to postbox and in particular its longer-term impact on children.