In this article, we analyze how clients in online counseling by email do complaining. Complaining is a "face-threatening act" and can jeopardize the relationship between interlocutors. In online health interventions, we see high dropout rates. We suggest that because the interaction between client and counselor is at the basis of counseling, it is important to understand how a communicative act (e.g., a complaint) that signals potential dropout is constructed sequentially. Based on a corpus of 20 email exchanges, we illustrate how clients constructed complaints over several sentences and sometimes various emails, and how they designed the complaints to minimize threat to the counselor's face. Counselors, in their responses, used various strategies to manage face threats. We show how complaints were mitigated to protect the counseling relationship and suggest that this is useful knowledge for health professionals. © The Author(s) 2014.