Mass e-mail campaigns are the organizational tool of choice for environmental activists seeking to inform and mobilize their constituencies. Some democratic theorists and reformers pin their hopes for more responsive and informed government policy on Internet-enhanced dialogue and debate. Electronic advocacy campaigns and action alerts are changing the nature and scope of public deliberation in contentious federal rulemaking. This paper examines the new digital landscape of electronic rulemaking through a case study of the recent mercury rulemaking at the US Environmental Protection Agency. Results are presented from an effort to code a sample of 1,000 e-mails selected at random from a dataset of approximately half a million. Particular attention is paid to the unique additions made to form letters.