This exploratory study shows how it is possible to rate and comment on L2 users’ written discourse in a way that takes the envisageable reactions to that discourse into consideration. The focus is on the written expression of the thanking illocution by L2 users and the reaction to it by expert L1 users (academic lecturers). The findings show that the L1 lecturers cared about both general communicative effectiveness (i.e. the Cooperative Principle) and transaction-specific social appropriateness (i.e. interlocutors’ awareness of their interactional roles). They also show that the (perceived) respect, violation, misunderstanding of social-textual norms triggered non-neutral, multi-faceted reactions from the lecturers, who revealed their emotional and cognitive experience and aesthetic appreciation of, moral judgement on, attitude towards or envisaged actional response to the interactions. Third, the lecturers appeared to be sensitive to the encoding of thank-you messages: they considered lexical choices responsible for the tone (interpretive key) of the texts. Finally, the lecturers’ ratings of the student texts along dimensions of communicative adequacy positively correlated with the appreciative/critical comments on the texts, showing that the encoding of the texts is a clue as to their social import, and to the (perceived) solidity of their writers’ communicative competence.