Thongdom P, Jaruvitayakovit T. Design and Evaluation of a High-Availability Secure Mail Relay with OAuth2 Authentication for Legacy Systems. J. Comput. Creat. Technol. [internet]. 2026 Apr. 21 [cited 2026 Sep. 11];4(1):e2971. available from: https://so13.tci-thaijo.org/index.php/jcct/article/view/2971