MAPI

Last updated

Messaging Application Programming Interface (MAPI) is an API for Microsoft Windows which allows programs to become email-aware. While MAPI is designed to be independent of the protocol, it is usually used to communicate with Microsoft Exchange Server. [1]

Contents

Details

MAPI uses functions loosely based on the X.400 XAPIA standard. It includes facilities to access message transports, message stores, and directories.

While Simple MAPI (SMAPI) is a subset of 12 functions which enable developers to add basic messaging functionality, Extended MAPI (EMAPI) allows complete control over the messaging system on the client computer. This includes creation and management of messages, plus management of the client mailbox, and service providers.

Simple MAPI is included with Microsoft Windows as part of Outlook Express/Windows Mail while the full Extended MAPI is included with Microsoft Outlook and Exchange.

In addition to the Extended MAPI client interface, programming calls can be made indirectly through the Simple MAPI API client interface, through the Common Messaging Calls (CMC) API client interface, or by the object-based CDO Library interface. These three methods are easier to use and designed for less complex messaging-enabled and -aware applications. (Simple MAPI and CMC were removed from Exchange 2003.)

MAPI was originally designed by Microsoft. The company founded its MS Mail team in 1987, but it was not until it acquired Consumers Software in 1991 to obtain Network Courier that it had a messaging product. Reworked, it was sold as MS PC Mail (or Microsoft Mail for PC Networking). The basic API to MS PC Mail was later known as MAPI version 0 (or MAPI0), to differentiate it from "true" MAPI.

Service provider interface

The full Extended MAPI interface is required for interfacing messaging-based services to client applications such as Outlook. For example, several non-Microsoft e-mail server product vendors created "MAPI service providers" to allow their products to be accessed via Outlook. Notable examples include Axigen Mail Server, Kerio Connect, Scalix, Zimbra, HP OpenMail, IBM Lotus Notes, Zarafa/Kopano, and Bynari.

MAPI also had a service provider interface of sorts. Microsoft used this to interface MS Mail to an email system based on Xenix, for internal use.

Extended MAPI is the main e-mail data access method used by Outlook, to interface to Microsoft Exchange, via MAPI service providers shipped with Outlook.

MAPI/RPC protocol details

Microsoft has released full details of the MAPI/RPC protocol since August 2007. [2]

"MAPI protocol" is a colloquial name for the MAPI/RPC. At times, Microsoft has also called it "Exchange RPC" and "Outlook-Exchange Transport Protocol".

Microsoft provides a sample MAPI/RPC-based application called MFCMAPI [3] to assist developers. It is also widely used as a diagnostics tool by both developers and Microsoft Exchange administrators.

MAPI over HTTP

The original implementation was designed for use on a local network, or LAN.

With Exchange 2003 and Outlook 2010, Microsoft introduced RPC over HTTP (later renamed Outlook Anywhere) as a way to Exchange over the internet. [4]

In 2014, Exchange 2013 SP1 introduced another variant, this time with a more "normal" HTTP-based stack known as "MAPI over HTTP". [5]

Incompatibility with Internet Mail

The Simple Mail Transfer Protocol has always supported the concept of mail with multiple authors, and distinguishes between the "sender" and "authors" whenever there is more than one of the latter. MAPI cannot represent separate authors and senders except through the delegation mechanism, which does not permit more than one author. Thus MAPI cannot accurately transmit group letters from scientific communities to legislators, or presentation of group research via email, or similar scenarios. When fully SMTP compliant mailers (e.g. Thunderbird) send perfectly formed SMTP messages with multiple authors into MAPI-dependent email infrastructures (such as Exchange/Outlook, O365, or Outlook.com) the messages must have their information density reduced to fit MAPI, presenting challenges for authentication and anti-spoofing technologies that rely on accurate message metadata transmission, and fundamentally changing messages to be something other than what was originally sent. Although the security implications impact all users, inability to represent multiple authorship is generally of little concern in purely hierarchical settings such as traditional businesses and military organizations, primarily impacting legislative and academic institutions.

Reimplementations

Several open-source software projects have started working on implementing MAPI libraries, including:

Related Research Articles

<span class="mw-page-title-main">Email</span> Mail sent using electronic means

Email is a method of transmitting and receiving messages using electronic devices. It was conceived in the late–20th century as the digital version of, or counterpart to, mail. Email is a ubiquitous and very widely used communication medium; in current use, an email address is often treated as a basic and necessary part of many processes in business, commerce, government, education, entertainment, and other spheres of daily life in most countries.

<span class="mw-page-title-main">Email client</span> Computer program used to access and manage a users email

An email client, email reader or, more formally, message user agent (MUA) or mail user agent is a computer program used to access and manage a user's email.

<span class="mw-page-title-main">Webmail</span> Email service that can be accessed using a web browser

Webmail is an email service that can be accessed using a standard web browser. It contrasts with email service accessible through a specialised email client software. Additionally, many internet service providers (ISP) provide webmail as part of their internet service package. Similarly, some web hosting providers also provide webmail as a part of their hosting package.

<span class="mw-page-title-main">SOGo</span>

SOGo is an open source collaborative software (groupware) server with a focus on simplicity and scalability.

Microsoft Exchange Server is a mail server and calendaring server developed by Microsoft. It runs exclusively on Windows Server operating systems.

The following tables compare general and technical features of notable email client programs.

<span class="mw-page-title-main">Microsoft Mail</span> Several Microsoft email products

Microsoft Mail was the name given to several early Microsoft e-mail products for local area networks, primarily two architectures: one for Macintosh networks, and one for PC architecture-based LANs. All were eventually replaced by the Exchange and Outlook product lines.

Collaboration Data Objects (CDO), previously known as OLE Messaging or Active Messaging, is an application programming interface (API) included with Microsoft Windows and Microsoft Exchange Server products. The library allows developers to access the Global Address List and other server objects, in addition to the contents of mailboxes and public folders.

The comparison of mail servers covers mail transfer agents (MTAs), mail delivery agents, and other computer software that provide e-mail services.

Bynari is a defunct company based in Dallas, developing server and email software, mainly known for its Insight Family, similar to Microsoft Exchange Server with Outlook.

Z-Push is a FOSS implementation of the Microsoft Exchange ActiveSync protocol which is used to synchronize email, personal contacts and other items between a central server and a mobile device.

<span class="mw-page-title-main">Zarafa (software)</span> Discontinued free and open-source groupware

Zarafa was an open-source groupware application that originated in the city of Delft in the Netherlands. The company that developed Zarafa, previously known as Connectux, is also called Zarafa. The Zarafa groupware provided email storage on the server side and offered its own Ajax-based mail client called WebAccess and a HTML5-based, WebApp. Advanced features were available in commercially supported versions. Zarafa has been superseded by Kopano.

Exchange ActiveSync is a proprietary protocol designed for the synchronization of email, contacts, calendar, tasks, and notes from a messaging server to a smartphone or other mobile devices. The protocol also provides mobile device management and policy controls. The protocol is based on XML. The mobile device communicates over HTTP or HTTPS.

Thank The MMS Architecture is the set of standards used by the Multimedia Messaging Service in mobile networks. The standards are prepared by 3GPP.

<span class="mw-page-title-main">Zentyal</span> Linux distribution

Zentyal is a open source email and groupware solution based on Ubuntu Linux. The latest release took place on February 26, 2024.

MailEnable is a Windows-based, commercial email server distributed by MailEnable Pty. Ltd, an Australian-based software company which was established in 2002.

The first release of Microsoft Exchange Server was version 4.0 in April 1996, when it was sold as an upgrade to Microsoft Mail 3.5. Before that, Microsoft Mail v2.0 was replaced in 1991 by "Microsoft Mail for PC Networks v2.1", based on Network Courier from its acquisition of Consumers Software. Exchange Server was an entirely new X.400-based client–server mail system with a single database store that also supported X.500 directory services. During its development, Microsoft migrated their own internal email from a Xenix-based system to Exchange Server from April 1993, with all 32,000 Microsoft mailboxes on Exchange by late 1996. The directory used by Exchange Server eventually became Microsoft's Active Directory service, an LDAP-compliant directory service. Active Directory was integrated into Windows 2000 as the foundation of Windows domains.

Kopano is an open-source groupware application suite originally based on Zarafa. The initial version of Kopano Core (KC) was forked from the then-current release of Zarafa Collaboration Platform, and superseded ZCP in terms of lineage as ZCP switched to maintenance mode with patches flowing from KC. Kopano WebApp similarly descended from Zarafa WebApp. Since October 2017, Kopano Core is also known more specifically as Kopano Groupware Core, since Kopano B.V. developed more products that were not directly requiring groupware components.

The JSON Meta Application Protocol (JMAP) is a set of related open Internet Standard protocols for handling email. JMAP is implemented using JSON APIs over HTTP and has been developed as an alternative to IMAP/SMTP and proprietary email APIs such as Google's Gmail and Microsoft's MAPI . Additional protocols and data models being built on top of the core of JMAP for handling contacts and calendar synchronization are meant to be potential replacements for CardDAV and CalDAV, and other support is currently in the works.

References

  1. "MAPI over HTTP in Exchange 2016". Microsoft TechNet . 2016-12-20.
  2. Exchange Server Protocols. Msdn.microsoft.com. Retrieved on 2013-07-17.
  3. Mfcmapi - Home. https://github.com/stephenegriffin/mfcmapi. Retrieved on 2017-07-26.
  4. "Exchange Server 2003 RPC over HTTP Deployment Scenarios". 2014-12-22. Archived from the original on 2014-12-22. Retrieved 2014-12-22.
  5. "Outlook Connectivity with MAPI over HTTP". You Had Me At EHLO…. Microsoft. Archived from the original on 2019-04-20. Retrieved 20 April 2019.
  6. openmapi.org used to host the downloads; it no longer exists
  7. "EWS Operations Features' Parity Matrix" . Retrieved 17 December 2018.