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EWS Managed API

Topic Last Modified: 2006-06-05

This glossary includes definitions for core concepts and technologies associated with Microsoft Exchange Server 2007.

Term Definition

absolute URL

A URL that has the full address necessary for locating a resource in an Exchange store.

access control entry (ACE)

An entry in an object's discretionary access control list (DACL) that grants permissions to a user or group. An ACE is also an entry in an object's system access control list (SACL) that specifies the security events to be audited for a user or group.

access control list (ACL)

A list of security protections that apply to an entire object, a set of the object's properties, or an individual property of an object. There are two types of access control lists: discretionary and system.

access mask

A 32-bit value that specifies the rights that are allowed or denied in an access control entry (ACE) of an access control list (ACL). An access mask is also used to request access rights when an object is opened.


See Other Term: access control entry (ACE)


See other term: access control list (ACL)


A workflow task that details how an item moves from state to state or executes a script. Multiple actions can be associated with a particular state.

action table

A set of rules, stored as an ADO Recordset, that define how workflow items can change state. Each row in an action table represents a possible state transition in the workflow.

Active Directory

The Windows-based directory service. Active Directory stores information about objects on a network and makes this information available to users and network administrators. Active Directory gives network users access to permitted resources anywhere on the network using a single logon process. It provides network administrators with an intuitive, hierarchical view of the network and a single point of administration for all network objects.

Active Directory Connector (ADC)

An Active Directory synchronization agent that provides an automated way of keeping directory information consistent between directories.

Active Directory contact

An Active Directory object that contains information about an individual such as name, address, and job title. It can include a foreign e-mail address. The Contact object is derived from the Person class but it is not a security principal and therefore cannot log on to the network or access any Exchange resources.

Active Directory Service Interfaces (ADSI)

A directory service model and a set of Component Object Model (COM) interfaces. ADSI enables Windows applications and Active Directory clients to access several network directory services, including Active Directory. ADSI is supplied as a software development kit (SDK).

ActiveX Data Objects (ADO)

A high-level, language-independent set of object-based data access interfaces that are optimized for data applications. ADO enables client applications to access and manipulate data from a database server through an OLE DB provider.


See other term: Active Directory Connector (ADC)


See other term: Active Directory Service Interfaces (ADSI)


A calendar item in the Exchange store. Appointments do not include other people or resources.

asynchronous event

A type of event that fires after a change has been fully committed to the Exchange store. Asynchronous events do not block the Exchange store thread but instead fire after the action has been committed.


A person invited to attend a meeting or appointment. An attendee can accept, decline, or ignore a meeting request. Represented by the Collaboration Data Objects (CDO) Attendee object.


A process by which software components and layers are linked together. When a network component is installed, the binding relationships and dependencies for the components are established. Binding allows components to communicate with each other.

calendar item

An item in the Exchange store. A calendar item can represent an appointment, a meeting, a meeting request, or an event. It can identify the place, resources, recurrence, and attendees involved at a discrete time.


See Other Term: Collaboration Data Objects (CDO)

class identifier (CLSID)

A universally unique identifier (UUID) that identifies a type of COM object. Each type of COM object item has its CLSID in the registry so that it can be loaded and used by other applications. For example, a spreadsheet may create worksheet items, chart items, and macrosheet items. Each of these item types has its own CLSID that uniquely identifies it to the system.


See Other Term: class identifier (CLSID)

Collaboration Data Objects (CDO)

An application programming interface that allows users and applications high-level access to data objects in Exchange. CDO defines the concept of different object classes, including messages, posts, appointments, and tasks.


An object that contains a set of other objects. An object's position in the collection can change whenever a change occurs in the collection; therefore, the position of any specific object in the collection may vary.

contact item

An item that represents a contact in the Exchange store.

container object

An object that can logically contain other objects. For example, a folder is a container object.

content class

A name identifying the intent or purpose of an item. Content class determines which Exchange store schema properties are associated with a resource when it is created.

coordinated universal time (UTC)

A universal timekeeping standard based on Greenwich Mean Time (GMT). Local time is calculated in UTC and offset by the local time zone.


See Other Term: discretionary access control list (DACL)

discretionary access control list (DACL)

The part of an object`s security descriptor that grants or denies specific users and groups permission to access the object. Only the owner of an object can change permissions granted or denied in a DACL; thus, access to the object is at the owner`s discretion.

dispatch ID

A 32-bit integer that identifies a property set.

distinguished folder

A unique folder in a mailbox that can be referenced by Web services requests to identify a folder by name.

distinguished name

A name that uniquely identifies an object by using the relative distinguished name for the object, plus the names of container objects and domains that contain the object. The distinguished name identifies the object as well as its location in a tree. Every object in Active Directory has a distinguished name. A typical distinguished name might be CN=MyName,CN=Users,DC=Microsoft,DC=Com. This identifies the MyName user object in the domain.


See Other Term: dynamic-link library (DLL)

Document Object Model (DOM)

A World Wide Web Consortium specification that describes the structure of dynamic HTML and XML documents in a way that allows them to be manipulated through a Web browser.


The term used to describe the deleted item recovery feature. When the dumpster is enabled, items emptied from the Deleted Items folder are placed in the dumpster for a server-configured number of days. A client can retrieve the items from the dumpster until the number of days has passed. Each folder has its own dumpster.

dynamic-link library (DLL)

An operating system feature that allows executable routines (generally serving a specific function or set of functions) to be stored separately as files with .dll extensions. These routines are loaded only when needed by the program that calls them.


The occurrence of some particular action or the occurrence of a change of state that can be handled by an event sink. For example, the arrival of a message to the Simple Mail Transport Protocol (SMTP) service is an event that can be handled by a number of event sinks.

event registration

An item that resides in a folder that uses an event sink. The item provides the store with information that includes what events will trigger the sink, the name of the sink, and options such as restrictions for when the event will fire. The event registration item can be created with either Microsoft ActiveX Data Objects or with a special script tool that can be used in batch files known as RegEvent.

event registration item

A hidden item that contains the ProgID of an event sink, information about what events will trigger the event sink, and options that tell when or under what conditions the event sink will be triggered. The event registration item is created in the same folder that is being monitored for events.

event sink

Code that gets activated through a defined trigger, such as the receipt of a new message. The code is normally written in any COM-compatible programming language, such as Microsoft Visual Basic; Microsoft Visual Basic, Scripting Edition; JScript; and C/C++. Exchange supports transport, protocol, and store event sinks. Event sinks on the store can be synchronous (code executes as the event is triggered) or asynchronous (code executes sometime after the event).


A specific appointment that is added, modified, or deleted from the pattern of a recurring appointment or meeting.

Exchange store

A storage platform that provides a single repository for managing multiple types of unstructured information in one infrastructure. The Exchange store combines the features and functionality of the file system, the Web, and a collaboration server (such as Microsoft Exchange) through a single, URL-addressable location for storing, accessing, and managing information, as well as building and running applications. The Exchange store is also known as the Web Storage System.

Exchange store schema

The data definition of a single Exchange store used to define all of the resources, such as folders, items, and Web files, found in the store. The schema consists of a large number of predefined schema properties, which determine the qualities, such as the creation date or the display name, of a resource.

folder tree

A hierarchy of folders in the Exchange store very similar in structure to the standard file system. A single folder can contain child folders, which, in turn, can contain other child folders.

free/busy status

The availability of a person. In addition to free/busy, the status can also be out-of-office (OOF) or tentative.


See Other Term: Global Address List (GAL)


See Other Term: global domain identifier (GDI)

Global Address List (GAL)

A list of users and other objects in a directory that contains information about those users and objects. In a hosting (shared) environment, the customer GAL is a list of objects that a customer is allowed to see. Permissions can be set on GALs so that certain customer data is isolated from other customers in a shared environment.

global domain identifier (GDI)

Specifies the country/region, the administration management domain (ADMD), and the private management domain (PRMD) of an X.400 e-mail address. For example c=us; a=MCI; p=msft.

hard delete

The process of permanently removing an item from the store or moving it to the dumpster when dumpster functionality is enabled. The dumpster is enabled/disabled by means of a registry setting on the computer running Exchange.


See Other Term: Hypertext Transfer Protocol (HTTP)

Hypertext Transfer Protocol (HTTP)

An Internet standard protocol that lets Web browsers like Microsoft Internet Explorer access Exchange stores. WebDAV is an extension to HTTP that you can use to build applications that are writable instead of just read-only.


See Other Term: Lightweight Directory Access Protocol (LDAP)

Lightweight Directory Access Protocol (LDAP)

The standard Internet protocol used for directory access. LDAP is the wire protocol used to conduct conversations between a client application and Active Directory across a network. An LDAP application can access any directory service that exposes an LDAP protocol.

mailbox store

A database for storing mailboxes in Exchange Server. Mailbox stores store data that is private to an individual and contain mailbox folders generated when a new mailbox is created for an individual. A mailbox store consists of a rich-text, .edb file, as well as a streaming native Internet content .stm file.

mail-enabled object

A type of object that has an e-mail address on a domain in the organization, but the object does not have a mailbox in the domain at which to receive messages. The object appears in the global address list, which allows other people in the organization to easily locate or send a message to that person, but the administrator does not need to manage an unnecessary mailbox. Contacts, users, and even folders can be mail-enabled.


See Other Term: Messaging Application Programming Interface (MAPI)


A calendar item that includes reserved resources and/or invited attendees.

message item

An implementation of the Internet Message Format defined by RFC2822. A message item is stored in the Exchange store.

message transfer envelope (MTE)

A MAPI message that holds the delivery information for a message. The MTE includes the addressing properties for each recipient, header information such as the sender and subject, and specifications for responding and exception handling. It encloses another MAPI message that contains the contents of the message to be delivered. MTEs are only created in gateway folders. In contrast, regular user folders contain the message contents only.

message transfer system (MTS)

The X.400 term for a messaging system, which is a product that enables electronic communication over a network.

Messaging Application Programming Interface (MAPI)

A messaging architecture that enables multiple applications to interact with different messaging systems across a variety of hardware platforms. MAPI is built on the Component Object Model (COM) architecture.


See Other Term: MIME Encapsulation of Aggregate HTML Documents (MHTML)


See Other Term: Multipurpose Internet Mail Extensions (MIME)

MIME Encapsulation of Aggregate HTML Documents (MHTML)

An Internet standard that defines the MIME structure used to send HTML content in message bodies along with elements used in a Web page.


See Other Term: message transfer envelope (MTE)


See Other Term: message transfer system (MTS)

Multipurpose Internet Mail Extensions (MIME)

A set of Internet Requests for Comment (RFCs) that define the format of messages to allow for textual message bodies, an extensible set of different formats for non-textual message bodies, multi-part message bodies, and textual header information in character sets other than US-ASCII. MIME is defined in RFCs 2045, 2046, 2047, 2048 and 2049.


A logical collection of properties in an Exchange store schema. A namespace serves to group related properties together for easy property discovery and, more importantly, to keep the property names unique. A Domain Name System (DNS) name creates a namespace; for example,

Network News Transfer Protocol (NNTP)

A member of the TCP/IP suite of protocols used to distribute network news messages to NNTP servers and clients (newsreaders) on the Internet. NNTP is designed so that news articles are stored on a server in a central database, thus enabling a user to select specific items to read.


A mechanism used in many systems for performing event-based processing, which allows the client to perform actions based on changes in the state of the server.


See Other Term: offline address book (OAB)

offline address book (OAB)

A copy of an address book that has been downloaded so that an Outlook user can access the information it contains while disconnected from the server.


Something that happens only once, or which is instantiated only once.


See Other Term: Post Office Protocol version 3 (POP3)

Post Office Protocol version 3 (POP3)

An Internet standard protocol that allows a user to download e-mail from his or her Inbox on a server to the client computer where messages are managed. This protocol works well for computers that are unable to maintain a continuous connection to a server.

property ID

A 32-bit integer that is used to identify a named property within a given property set. Note that property IDs and property names are mutually exclusive.

property name

A string value that is used to identify a named property within a given property set. Note that property names and property IDs are mutually exclusive.

property set

A GUID that defines a namespace for a set of properties. Property sets can be well known or nonstandard.

property tag

A 32-bit value that represents a property in the store. Property tags can have reserved and custom ranges.

public store

A database for storing public folders in Exchange. A public store can be accessible to everyone in an organization or can be restricted to a subset of individuals such as a department or team.

recipient policy

A policy that is applied to mail-enabled objects to generate e-mail addresses. Recipient policies can be defined to apply to thousands of users, groups, and contacts in Microsoft Active Directory by using a Lightweight Directory Access Protocol (LDAP) query interface in a single operation.

recursive event

An event that can be registered for a parent folder as well as for any child folders.

relative URL

A form of URL in which the protocol, domain, and some or all directory names are omitted.

remote procedure call (RPC)

A message-passing facility that allows a distributed application to call services that are available on various computers on a network. Used during remote administration of computers.


Anything placed in the Exchange store. A resource can be an e-mail message, an appointment, another folder, a Web page, or any structured document, such as a Microsoft Excel spreadsheet.


See Other Term: system access control list (SACL)

Secure Multipurpose Internet Mail Extensions (S/MIE)

An extension of MIME that supports secure mail. It enables message originators to digitally sign e-mail messages to provide evidence of message origin and to ensure data integrity. It also enables messages to be transmitted in encrypted format to provide confidential communications.

security descriptor

A data structure that contains information about the security attributes for an Exchange store resource, including a list of users and groups that have access permissions to the resource.

security identifier (SID)

In Windows-based systems, a unique value that identifies a user, group, or computer account within an enterprise. Every account is issued a SID when it is created.


The logic that serves as the underpinning of programming syntax. A program that is syntactically correct can be semantically incorrect.


See Other Term: security identifier (SID)

Simple Mail Transfer Protocol (SMTP)

A member of the TCP/IP suite of protocols that governs the exchange of electronic mail between message transfer agents (MTA). SMTP is the default transport for Exchange Server.


See Other Term: Simple Mail Transfer Protocol (SMTP)


A type of tool that you can add to a console supported by Microsoft Management Console (MMC). A standalone snap-in can be added by itself; an extension snap-in can be added only to extend the function of another snap-in. A snap-in is used to manage services for a component or product. Exchange System Manager is an example of an MMC snap-in.

soft delete

The process of moving an item to the Deleted Items folder.


The status of an item in a workflow process. As an item moves through a workflow process, it assumes different states. You use an item's state to track its progress through a workflow process. A state can have multiple actions associated with it.

storage group

A collection of mailbox stores and public folder stores that share a set of transaction log files. Exchange manages each storage group with a separate server process.


Technology used by Exchange to store user mailboxes and folders. There are two kinds of stores: mailbox stores and public stores. A store consists of a rich-text database (.edb), plus a streaming native Internet content database (.stm).

synchronous events

Events that fire immediately before an item is committed to the Exchange store. These events block the Exchange store thread until the event thread has finished executing. While executing, a synchronous event has exclusive control over the item that triggered the event. No other process or request can access the item until the event sink is finished executing.

system access control list (SACL)

The part of an object`s security descriptor that specifies which events are to be audited per user or group. Examples of auditing events are file access, logon attempts, and system shutdowns.

system events

Events that are not tied to any particular item or folder in the Exchange store. Instead, they are associated with general actions such as the starting of a database or the system clock reaching a certain time. Within their context, they behave as asynchronous events and do not fire until after the Exchange store has completed the action triggering the event.


A set of independent operations that are bundled together and performed as an atomic operation; the operations succeed or fail as a whole.


See Other Term: coordinated universal time (UTC)


An encoding mechanism that converts binary data into printable ASCII characters so that the data can be included in the message body without violating SMTP conventions.

virtual directory

A name used to access the contents of any Exchange store using a Web browser. The virtual directory name is used to open a mailbox as well as browse the folders of a public store. This name is also used in URLs using the Microsoft Internet Publishing Provider (MSDAIPP), which includes both hyperlinks in Web pages as well as Microsoft ActiveX Data Objects client-side code.


See Other Term: Volume Shadow Copy Service (VSS)

Web Distributed Authoring and Versioning (WebDAV)

An extension of Hypertext Transfer Protocol (HTTP) 1.1 that allows clients to perform remote Web content authoring. Content that is stored on a server can be accessed by a client through HTTP by using WebDAV extensions. The client can perform tasks provided by HTTP, including reading e-mail and documents. If the client also supports WebDAV, the client can manipulate mail, change calendar appointments, modify and create new documents on the Exchange server, and create Web-based forms. WebDAV uses Extensible Markup Language (XML) as the format for transmitting data elements.

Web reference

A reference that provides access to an available resource by using an Internet protocol such as SOAP or HTTP.

Web services

A software application identified by a Uniform Resource Identifier (URI), the interfaces and binding of which are capable of being defined, described, and discovered by XML artifacts and which supports direct interactions with other software applications that are using XML-based messages by means of Internet-based protocols.

Web Services Description Language (WSDL)

An XML format developed to allow for better interoperability among Web services and development tools. WSDL describes network services as collections of communication endpoints capable of exchanging messages and is extensible to allow descriptions of endpoints and their messages regardless of what message formats or network protocols are used to communicate. WSDL enables Web services providers and users to work together easily by enabling the separation of the description of the abstract functionality offered by a service from the concrete details of a service description such as "how" and "where" that functionality is offered.


See Other Term: Web Distributed Authoring and Versioning (WebDAV)

WebDAV protocol

A protocol that can be used to access items in an Exchange store. The WebDAV protocol provides a means to access not only the contents of an item but also an extensible set of associated properties. Also known as the HTTP/DAV or DAV protocol.


Server-side logic that you can use to route items in a folder from one user to another and enforce and track an item throughout its lifetime.

workflow engine

An in-process server (CDOWF.DLL) that implements the IProcessInstance Advance method.


An international messaging standard that can be used by a variety of messaging systems. X.400 uses a strict addressing method that reflects a hierarchical environment. The use of X.400 has been largely supplanted by the combination of SMTP and MIME.