Incoming messages from the Internet or local clients are received by the MTA through the Simple Mail Transport Protocol (SMTP). If the address is internal, that is, within the Messaging Server domain, the MTA delivers the message to the Message Store. If the message is external, that is, addressed to a domain outside of Messaging Server control, the MTA relays the message to another MTA on the Internet.
Although it is possible to deliver mail to the /var/mail file system (UNIX systems only), which was the case in previous versions of the Messaging Server, local messages are usually delivered to the more optimized Messaging Server Message Store. Messages are then retrieved by IMAP4, POP3, or HTTP mail client programs.
New users and groups are created by adding user and group entries to the directory. Entries can be created or modified by using the Delegated Administrator utility or by modifying the directory using LDAP.
Messaging Server provides a set of command-line administrative interfacs and configuration files. Some of the more common administrative tasks are adding, modifying, and removing users and groups to the mail system, and configuring the operation of the MTA, directory server, and Message Store.