Messaging overview

The IBM® Domino® mail system has three basic components: Domino mail servers, Domino mail files, and mail clients. The Domino mail server is the backbone of an organization's messaging infrastructure, acting both as an Internet mail server and an IBM Notes® mail server. Domino provides standards-based Internet messaging through its support of the Simple Mail Transfer Protocol (SMTP), Post Office Protocol version 3 (POP3), Internet Message Access Protocol (IMAP), and Multipurpose Internet Mail Extensions (MIME). At the same time, Domino supports Notes mail through the use of Notes routing protocols -- Notes remote procedure calls (NRPC) -- and the Notes rich text message format.

Domino mail servers provide services that directly and indirectly support messaging. These include specialized databases for locating users and servers, for message storage and transit, and for collecting statistics; and processes that initiate and receive connections between servers, route messages, and allow users to retrieve mail.

Every mail user in a Domino system has a mail file on a Domino mail server. You can create a replica of the mail file on other servers for failover in case the primary server is unavailable. Users create mail messages using a mail client, such as Notes , or a POP3 or IMAP client, and send mail through the Domino mail server, which routes the message to its recipient. The recipient then uses a mail client to read the message. To protect confidential information in mail messages, Domino supports Notes public key encryption and S/MIME encryption.

The Notes client and the Domino mail router (the Router) create and send messages in the format (MIME or Notes rich text) appropriate for each recipient, as determined from the address format and settings in the recipient's Person document. If conversion between formats is necessary, Domino performs the conversion automatically.

The Router uses information in the Domino Directory to determine where to send messages and what transfer protocol to use. For messages sent over SMTP, the Router also uses information from the Domain Name System (DNS).

Domino provides tools for monitoring mail, controlling unsolicited commercial e-mail (UCE), and preventing unauthorized access to the mail system. To reduce the space needed to store users’ mail, you can set quotas on users’ mail files or restrict users from creating full-text indexes. Domino provides migration tools and message transfer agents to help you move from a heterogeneous system to a Domino mail server, which combines support for Notes mail alongside support for Internet mail standards.

You can also reduce storage space needs by consolidating attachment files through the use of the Domino Object and Attachment Service (DAOS) on the server.