The aim of the study is to determine the quality of machine translation of English press releases into Russian in terms of semantic, stylistic and communicative adequacy. The article considers examples of communicative failures and analyses the reasons for the inadequacy of machine translation. The scientific novelty of the research consists in revealing violations of linguistic norms of the Russian language in the translated text of informative governmental press releases characterized by the high diplomatic style. The study found that communicative failures – violations of the norms of the Russian language – occur as a result of literal translation without analyzing the wider linguistic context, selection of an adequate meaning or significant translation transformations at the level of syntactic constructions, such as modulation, displacement, omission, addition, and others. Avoiding such communicative failures requires training of the machine translation system in the rules of the Russian language, English-Russian translation equivalents corresponding to the official business style, and replenishment of the language base.