Letter-writing is an essential skill for vocational high school students because it prepares them for professional communication in workplace settings. However, many students still experience difficulties in organizing ideas, applying appropriate language features, and producing well-structured formal letters. Therefore, this study addresses the limited availability of contextual digital learning materials for vocational letter-writing by developing letter-writing e-module through Project-Based Learning (PBL) and Think-Pair-Share (TPS) for vocational high school students and to examine its feasibility and students’ responses. This research employed a Research and Development (R&D) design using the ADDIE model, consisting of Analysis, Design, Development, Implementation, and Evaluation. The participants were 24 eleventh-grade students of the Software and Game Development (PPLG) program at SMK BPI Bandung. Data were collected through classroom observations, teacher interviews, practitioner validation, and student response questionnaires. The validation process demonstrated that the developed e-module met appropriate pedagogical, instructional, and linguistic criteria. The validators confirmed that the e-module demonstrated appropriate content organization, learning activities, visual presentation, and language use, indicating its suitability as a learning resource for vocational high school students. Furthermore, students' responses were categorized as very positive, with response percentages of 87.50% in the limited field trial and 88% in the main field trial. These findings indicate that the developed e-module is feasible, practically applicable, and well accepted by vocational high school students. The integration of Project-Based Learning (PBL) and Think-Pair-Share provided structured opportunities for collaborative learning and authentic writing practice, making the e-module a promising instructional resource for teaching professional letter-writing in vocational education.