The MTA

The Messaging Server MTA is a general-purpose, store-and-forward system for distributing computer-based mail. The term store-and-forward means that the Messaging Server MTA  automatically handles the requeuing and retransmission of mail messages  necessitated when network links or services are temporarily  unavailable. In contrast to mail user agents (MUAs) such as Messenger Express or Communications Express (UWC) which are used to create and read electronic  mail messages, the Messaging Server MTA is a mail transport  agent (MTA) responsible for directing messages to the appropriate  network transport and ensuring reliable delivery over that transport.

The MTA provides a uniform distribution environment that can be interfaced to multiple user interfaces (MUAs), networks, protocols, and  transport mechanisms. As this interfacing, from the user&#x27;s point of view, is accomplished transparently, the MTA presents to the user a  homogeneous mail network; i.e., the MTA seamlessly blends  heterogeneous mail networks into a single, coherent mail system.

There are many components to the MTA.

See also:
 * Channels
 * Rewrite rules
 * Aliases
 * Mailing lists
 * Mapping tables
 * Message conversions
 * MTA options
 * MTA Tailor options
 * Dispatcher
 * Job Controller
 * Compiling the MTA configuration
 * Mail filtering and access control
 * Spam and virus filtering
 * MeterMaid
 * Notification messages
 * Message tracking and recall
 * TCPIP channels
 * ims-ms channels
 * Other channels
 * SMS options
 * Message capture
 * Monitoring the MTA
 * MTA transaction logging
 * MTA performance tuning
 * Restricting information emitted
 * MTA command line utilities