MAPI

Messaging Application Programming Interface (MAPI) is a messaging architecture and a Component Object Model based API for Microsoft Windows. MAPI allows client programs to become (e-mail) messaging-enabled, -aware, or -based by calling MAPI subsystem routines that interface with certain messaging servers. These servers include Microsoft Exchange, Microsoft Outlook, and other messaging systems that follow the MAPI standard. MAPI is used by many Microsoft and non-Microsoft products to integrate with the rich messaging capabilities of Outlook and Exchange.

Overview

MAPI defines a set of functions and objects to access messaging functions on both the client and server. It provides a complex set of APIs that abstract the underlying messaging system. With MAPI, developers can create messaging-enabled and messaging-aware applications. MAPI supports features such as sending email, creating calendar events, accessing the address book, and managing mail objects within a mailbox.

Components

MAPI consists of several components, including:

• MAPI Client: An application that uses MAPI to send and receive messages.
• MAPI Server: A messaging system that responds to requests from MAPI clients.
• MAPI Subsystem: A set of DLLs that provide the MAPI interface and manage communication between MAPI clients and servers.

Functionality

MAPI provides a wide range of functionality, including:

• Email creation, sending, and receiving
• Calendar event management
• Address book access
• Mailbox management

MAPI vs. SMTP/POP/IMAP

While MAPI provides rich messaging functionality, it is often compared to other email protocols such as SMTP, POP, and IMAP. SMTP is used for sending emails, while POP and IMAP are used for retrieving emails from a server. MAPI, on the other hand, offers a broader set of features beyond email sending and retrieval, including integration with calendars, tasks, and contacts.

Usage

MAPI is widely used in enterprise environments where Microsoft Exchange is the email server. Applications such as Microsoft Outlook leverage MAPI to provide integrated messaging solutions. Additionally, third-party applications can use MAPI to integrate with Outlook and Exchange for enhanced messaging capabilities.

Development

Developing MAPI applications requires knowledge of COM and the MAPI subsystem. Microsoft provides the MAPI header files and libraries as part of the Windows SDK. Developers can use languages such as C++ and Delphi to create MAPI applications.

Limitations and Alternatives

While MAPI provides extensive messaging capabilities, it is primarily tied to Microsoft platforms and products. For cross-platform messaging solutions, developers might consider using web-based APIs such as RESTful services provided by email providers. Additionally, with the rise of cloud-based email services, the use of MAPI has declined in favor of these more flexible and accessible solutions.

See Also

• Microsoft Exchange Server
• Microsoft Outlook
• Simple Mail Transfer Protocol (SMTP)
• Post Office Protocol (POP)
• Internet Message Access Protocol (IMAP)