message handling system (OSI) (MHS)

Message Handling System (MHS) is the generic term for a standards-compliant message transmission system. In general, it is understood to mean electronic mail as described in X.400.

The term electronic mail, e-mail, is associated with a computer-based telecommunications service that can transmit machine-processable documents from the sending user, the mail client, through the transferring facility, the mail server, and also cache them as needed. It is thus a service that supports asynchronous communication.

The transmitted documents can basically contain text, graphics, rasterized images, voice sequences or data. However, electronic mail also implies that the reader of these documents is human. However, this does not mean that electronically transmitted documents can be further processed with electronic tools. In view of the importance of MHS systems, various international organizations have been working on their standardization for several years. This cooperation resulted in recommendations which were adopted by the ITU-C in 1984.

Message handling systems are specified by the International Standards Organization( ISO) under ISO 10021.