To understand when patients use secure e-mail messaging with healthcare providers across several types of questions or concerns, associations between out-of-pocket costs for in-person visits and use of secure messaging, and to examine patient-reported impacts on care-seeking behavior and overall health. Cross-sectional survey of patients in an integrated healthcare delivery system, with access to a patient portal to send secure e-mail messages to providers at no out-of-pocket cost. The study included patients with a chronic condition (N = 1041). We described patient-reported preferences for contacting providers and patient-reported impact of e-mail use on phone calls, in-person visits, and overall health. We used multivariate analyses to examine patient characteristics associated with using e-mail as a first contact method, and effects on care-seeking and health. Overall, 56% of patients sent their provider an e-mail within 1 year, and 46% reported e-mail as their first method of contact for 1 or more types of medical concerns. After adjustment, higher out-of-pocket costs for in-person visits were significantly associated with choosing e-mail as a first method of contact (P < .05). Among patients who had e-mailed their provider, 42% reported that it reduced their phone contacts, 36% reduced in-person office visits and 32% reported e-mailing improved their overall health. Patients reported using e-mail broadly to initiate conversations with their providers, and patients with higher out-of-pocket costs for in-person visits were more likely to choose e-mail as a first contact method. Use of secure e-mails reduced patients' use of other types of healthcare and resulted in improved overall health.