M

mail user
See messaging user.
MAPI
(Messaging Application Programming Interface) A messaging architecture and a client interface component.

As a messaging architecture, MAPI enables multiple applications to interact with multiple messaging systems across a variety of hardware platforms. See also MAPI subsystem, messaging system.

As a client interface component, MAPI is the complete set of functions and object-oriented interfaces that forms the foundation for the MAPI subsystem's client application and service provider interfaces. In comparison with Simple MAPI, Common Messaging Calls (CMC), and the Active Messaging Library, MAPI provides the highest performance and greatest degree of control to messaging-based applications and service providers.

MAPI configuration file
A configuration file, MAPISVC.INF, that contains information about every message service and service provider installed on a workstation. For more information, see Message Services and Profiles.
MAPI interface
A set of related methods that describe the behavior of a MAPI object. All MAPI interfaces derive from the OLE base interface, IUnknown.
MAPI object
An object that supports the OLE Component Object Model (COM), implementing one or more interfaces derived from the IUnknown interface. It is implemented or used by a MAPI compliant service provider or client application, or by MAPI itself.
MAPI spooler
A MAPI process that handles the sending and receiving of messages between client applications and most messaging systems. A tightly coupled message store and transport provider does not use the spooler. See also client application, messaging system.
MAPI subsystem
The set of dynamic-link libraries (DLLs) provided by MAPI that enable interaction between client applications and service providers. The MAPI subsystem DLLs implement the MAPI spooler, the client interface, the service provider interface, and the support object.
message
A MAPI object containing information that can be sent to one or more recipients by means of a messaging system, or posted to a public folder. The principal parts of a message are the message content and the message envelope. Messages implement the IMessage : IMAPIProp interface. See also message text, post, recipient.
message body
See message text.
message class
A character string property that is assigned to every MAPI message, identifying the type of the message. The message class determines behavior such as selecting the appropriate receive folder and launching a form for the message. Message class strings are stored in the PR_MESSAGE_CLASS property.
message content
The portion of a message representing the information the sender wishes to communicate to each recipient. The message content includes the message text and any attachment objects. It excludes the message envelope. Messages of the same message class are expected to have similar content structure.
message envelope
The portion of a message used for routing and delivery to each recipient. The message envelope includes the address properties for each recipient, header information such as the sender and subject, and specifications for responding and exception handling. It excludes the message content. See also message text, message transfer envelope.
message identifier
An ASCII string used by Simple MAPI to access an incoming message. A message identifier is valid only during the session in which it is assigned a value by the MAPIFindNext function, and does not correspond to the message reference used by CMC. For more information, see Receiving a Message: Simple MAPI Sample.
message preprocessor
A dynamic-link library (DLL) that runs on a client workstation and operates on outbound messages before they are given to any transport provider. For example, a message preprocessor might make a local copy of every outgoing message. A message preprocessor can be called selectively based on each recipient's address type or entry identifier. Also referred to as a preprocessor. See also messaging hook provider. For more information, see Developing a Hook Provider or Preprocessor.
message reference
A counted string structure used by CMC to access a message within a mailbox. A message reference is valid only during the session in which it is assigned a value by the cmc_list function, and does not correspond to the message identifier used by Simple MAPI.
message service
A group of one or more related service providers installed and configured by a single body of code. For example, CompuServe might furnish an address book provider, message store provider, and transport provider all designed to interface with the CompuServe message service. For more information, see Message Services and Profiles.
message service table
A MAPI table object that provides access to information about every message service in the current profile, such as the service's name, service providers, and associated files.
message site
A MAPI object that handles the manipulation of form objects. Message site objects implement the IMAPIMessageSite : IUnknown interface.
message store
A MAPI object that contains messages and folders organized hierarchically and that implements the IMsgStore : IMAPIProp interface. See also folder, message.
message store provider
A MAPI service provider object that manages one or more message stores, handling message distribution, organization, and storage. Message store providers implement the IAttach : IMAPIProp, IMAPIFolder : IMAPIContainer, IMessage : IMAPIProp, IMsgStore : IMAPIProp, IMSLogon : IUnknown, and IMSProvider : IUnknown interfaces. For more information, see Developing a Message Store Provider.
message store table
A MAPI table object that provides access to information about every message store in the current profile.
message text
The principal content of an interpersonal message, that is, a message of message class IPM.Note. Message text can optionally be used in other message classes. It is the main portion of the message content, typically displayed to each recipient as an immediate result of opening the message. It excludes any attachment objects. Also referred to as the message body.
message transfer agent
(MTA) The X.400 term for the part of a message transfer system (MTS) that interfaces with clients of that MTS. A MAPI transport provider commonly interfaces with a message transfer agent.
message transfer envelope
(MTE) The X.400 term for the P1 or delivery envelope, which contains the information needed to deliver a message, as opposed to the information used to display it to a recipient. See also message envelope. For more information, see the PR_RECIPIENT_TYPE property.
message transfer system
(MTS) The X.400 term for a messaging system.
messaging application
A program that uses the MAPI client interface to pass messaging requests, such as requests to send and receive messages, to and from a messaging system. A messaging application is a type of client application.
messaging domain
A collection of interconnected messaging users that share a common addressing scheme and transport protocol. Communication with a messaging user in the same messaging domain does not involve reformatting or address translation. Communication with a messaging user in another messaging domain typically requires the use of a gateway. Also referred to as a domain or a site.
messaging hook provider
A MAPI service provider object that runs on the same machine as the MAPI spooler and performs special processing on inbound and outbound messages. Messaging hook providers implement the ISpoolerHook : IUnknown interface. A messaging hook provider can be called for all inbound messages, all outbound messages, or both. Also referred to as a spooler hook or a hook provider. See also message preprocessor. For more information, see Developing a Hook Provider or Preprocessor.
messaging service
See message service.
messaging system
A product that enables electronic communication over a network, such as fax, CompuServe, or the Internet. Typical clients of a messaging system include an individual computer with a modem and a local area network with a gateway.
messaging transport provider
See transport provider.
messaging user
A MAPI object that describes an individual recipient of a message. Messaging users implement the IMailUser : IMAPIProp interface. See also distribution list.
MIME
(Multipurpose Internet Mail Extensions) A set of enhancements to SMTP allowing an Internet message to include a mixture of audio, image, video, and text components, and to accommodate a variety of international character sets. MIME messages are identified by a MIME header in the top level of the SMTP header. The MIME mechanisms are specified in the RFC 1341 document.
MTA
See message transfer agent.
MTE
See message transfer envelope.
MTS
See message transfer system.
multivalued property
A property that can contain many values of the same type. Its property type has MV_FLAG set, and its property value contains multiple values of the specified property type. See also single-valued property. For more information, see About Property Types.