This paper investigates a set of email negotiations in order to explain a high number of deadlocks. The paper argues that one reason is the combination of cognitive effort characteristic of the e-mail genre, and the argumentative pattern found when two parties simultaneously try to persuade the other of the justice of their cause. For a negotiation involving the wording of a contract, the evidence suggests that, while there is a distinct advantage in the features of reviewability and revisablity, the email format allows selective attention to the other party’s arguments, which can be shown to block suggestions and lead to sub-optimal results.