Many organizations are currently experimenting with providing help services via e-mail. This investigation used content analysis of service logs and interviews with staff and users of a successful service to identify participants models of ideal exchanges and the impacts of the communication medium on service provision. Participants' models of ideal exchanges include single concise question/response pairs and extended dialogue. Staff are more likely to consider dialogue as typical, while users seem to almost exclusively consider the minimum exchange as normal. Content analysis of service logs suggests that most exchanges are simple question/answer pairs and that users tend to make explicit requests for instructions, explanations, brief informational answers to specific questions, or staff action on behalf of the user. Interviewees identified a range of both benefits and limitations conferred by the use of e-mail as the main medium of communication. While e-mail offers real benefits in terms of increased service access, convenience, and staff efficiency, it also makes service provision subject to time lags and loss of communication richness. One of the main problems participants face is the frequent occurrence of incomplete information. Users tend to either underspecify their request or omit needed information while staff often respond incompletely to queries. Evidence was also found to support the idea that users may feel freer to express negative attitudes and emotions via e-mail as opposed to face-to-face communication. This research suggests that the use of e-mail powerfully influences both the nature of a help service and its perception by users.