Description: The X.400 standard is a set of norms for electronic messaging defined by the International Telecommunication Union (ITU-T). This standard was designed to facilitate interoperability between different email systems, allowing messages to be sent and received efficiently across various platforms and networks. X.400 focuses on the structure and format of messages, as well as the communication protocols necessary for their transmission. Unlike other messaging systems, X.400 provides advanced security and reliability features, making it particularly suitable for business and government environments where information integrity is crucial. Additionally, it includes mechanisms for guaranteed message delivery, ensuring that data reaches its destination without loss or alteration. In a world where digital communication is essential, the X.400 standard has remained relevant, offering a robust framework for electronic messaging in various applications, including corporate email and communication between diverse information systems.