BACKGROUND The Caring Letters Project (CLP) is a suicide prevention program that involves sending brief caring letters to discharged inpatients following psychiatric hospitalization. Several studies suggest that repeatedly sending caring messages may reduce suicides and suicide attempts in high-risk populations. OBJECTIVE The aims of this study were to (1) evaluate feasibility of use in the military setting, (2) explore trends toward reduction of psychiatric rehospitalizations, (3) assess preference for and test e-mail correspondence, and (4) identify best practices and gather data to inform a randomized controlled study. METHODS A total of 110 psychiatric inpatients at a military treatment facility consented, were interviewed, and then received personalized handwritten letters or e-mails at regular intervals following discharge. Data collected included demographics, clinical characteristics, preference for e-mail versus postal mail, rates of undeliverable and return correspondence, rehospitalizations, and adverse events requiring safety procedures. RESULTS A total of 436 letters and e-mails have been sent to date. Most participants indicated preference for e-mail versus postal mail. Fifteen participants were readmitted for treatment compared to 20 patients in usual care. Twenty participants sent responses and all were positive statements about the program. There were no adverse events. CONCLUSIONS This program is feasible for use at a military treatment facility. A randomized controlled trial is needed to determine whether the intervention can reduce suicide rates among military and veteran populations.