Many emails display stylistic features of casual talk more than of formal writing. Two main explanations have been put forward for this phenomenon: It could either be the result of a hybrid of speaking and writing (the hybrid hypothesis), or the consequence of carelessness regarding the norms for the written language (the normative filter hypothesis). This study addresses the question of to what extent these explanations are plausible from the receiver’s perspective. Two experiments were conducted with a 2x2-design: messages presented in both classical letter format on paper and email format on screen versus messages presented in a manipulated style and in a style that is conventional for written Dutch. In the first experiment, the style manipulation incorporated features of the spoken language. The manipulation of the messages in the second experiment incorporated a variety of deviations from the conventions for writing – orthography, punctuation, grammar, and style – in the Dutch language. If the hybrid hypothesis holds, in the first experiment we expect that the negative effect of the implementation of speechlike constructions will be stronger in the messages on paper than in the electronic messages. If the normative filter hypothesis holds, in the second experiment we expect that readers of the messages with deviations will be more indulgent of them when they appear in emails than in letters on paper. The results give no evidence for the hybrid hypothesis, but some evidence for the normative filter hypothesis.