The structure of an MHS message is shown in figure 11.9. It consists of a message envelope and a message content. As with a postal message, the envelope represents the information required by the MTS to deliver the message, such as the address(es) of the recipient(s) and any special handling instructions. Many X.400 security parameters are transferred on the message envelope. The message content represents the information that the originator wants conveyed to the message recipient(s).
Figure 11.9: MHS Message Structure.