Overview of Exchange services on Exchange servers

During the installation of Exchange Server 2016 or Exchange Server 2019, Setup runs a set of tasks that install new services in Microsoft Windows. A service is a background process that can be launched during the startup of the server by the Windows Service Control Manager. Services are executable files designed to operate independently and without administrative intervention. A service can run using either a graphical user interface (GUI) mode or a console mode.

All previous versions of Exchange included components that are implemented as services. Each Exchange server role includes services that are part of (or may be needed by) the server role to perform its functions. Note that some services only become active when specific features are used.

The sections in this topic describe the various services that are installed by Exchange 2016 and Exchange 2016 on Mailbox servers and Edge Transport servers. For services that are labeled as optional, you can disable the service if you determine your organization doesn't need the functionality that's provided by the service.

Exchange services on Mailbox servers

The following table describes the Exchange services that are installed on Mailbox servers.

Service name Service short name Description and dependencies Default startup type Security context Dependencies Required or optional
Microsoft Exchange Active Directory Topology MSExchangeADTopology Provides Active Directory topology information to Exchange services. If this service is stopped, most Exchange services can't start. Automatic Local System Net.TCP Port Sharing Service Required
Microsoft Exchange Anti-spam Update MSExchangeAntispamUpdate Provides Exchange SmartScreen spam definition updates.
Note: In November, 2016, Microsoft stopped producing spam definition updates for the SmartScreen filters in Exchange and Outlook. The existing SmartScreen spam definitions were left in place, but their effectiveness will likely degrade over time. For more information, see Deprecating support for SmartScreen in Outlook and Exchange.
Automatic Local System Microsoft Exchange Active Directory Topology Optional
Microsoft Exchange Compliance Audit MSComplianceAudit Provides Exchange auditing features. Automatic Local System Microsoft Exchange Active Directory Topology Required
Microsoft Exchange Compliance Service MSExchangeCompliance Provides a host for Exchange compliance services. Automatic Local System Microsoft Exchange Active Directory Topology Required
Microsoft Exchange DAG Management MSExchangeDagMgmt Provides storage and database layout management for Mailbox servers in database availability groups (DAGs). Automatic Local System Microsoft Exchange Active Directory TopologyNet.TCP Port Sharing Service Required
Microsoft Exchange Diagnostics MSExchangeDiagnostics Provides an agent that monitors Exchange server health. Automatic Local System None Required
Microsoft Exchange EdgeSync MSExchangeEdgeSync Replicates configuration and recipient data between the Mailbox server and Active Directory Lightweight Directory Services (AD LDS) on subscribed Edge Transport servers over a secure LDAP channel.
If you don't have any subscribed Edge Transport servers, you can disable this service.
Automatic Local System Microsoft Exchange Active Directory Topology Optional
Microsoft Exchange Frontend Transport MSExchangeFrontEndTransport Proxies SMTP connections from external hosts to the Microsoft Exchange Transport service on Mailbox servers (the local server or remote servers). Automatic Local System Microsoft Exchange Active Directory Topology Required
Microsoft Exchange Health Manager MSExchangeHM Part of managed availability that monitors the health of key components on the Exchange server. Automatic Local System Windows Event LogWindows Management Instrumentation Required
Microsoft Exchange Health Manager Recovery MSExchangeHMRecovery Part of managed availability that attempts to recover unhealthy components on the Exchange server. Automatic Local System • Windows Event Log
• Windows Management Instrumentation
Required
Microsoft Exchange IMAP4 MSExchangeIMAP4 Proxies IMAP4 client connections from the Client Access (frontend) services to the backend IMAP4 service on Mailbox servers. By default, this service isn't running, so IMAP4 clients can't connect to the Exchange server until this service is started.
If you don't have any IMAP4 clients, you can disable this service.
Manual Local System Microsoft Exchange Active Directory Topology Optional
Microsoft Exchange IMAP4 Backend MSExchangeIMAP4BE Receives proxied IMAP4 client connections from the from the Client Access (frontend) IMAP4 service. By default, this service isn't running, so IMAP4 clients can't connect to the Exchange server until this service is started.
If you don't have any IMAP4 clients, you can disable this service.
Manual Network Service Microsoft Exchange Active Directory Topology Optional
Microsoft Exchange Information Store MSExchangeIS Manages the mailbox databases on the server. If this service is stopped, mailbox databases on the server are unavailable. Automatic Local System • Microsoft Exchange Active Directory Topology
• Remote Procedure Call (RPC)
• Server
• Windows Event Log
• Workstation
Required
Microsoft Exchange Mailbox Assistants MSExchangeMailboxAssistants Performs background processing of mailboxes in mailbox databases on the server. Automatic Local System Microsoft Exchange Active Directory Topology Required
Microsoft Exchange Mailbox Replication MSExchangeMailboxReplication Processes mailbox moves and move requests. Automatic Local System Microsoft Exchange Active Directory TopologyNet.TCP Port Sharing Service Rquired
Microsoft Exchange Mailbox Transport Delivery MSExchangeDelivery Receives SMTP messages from the Microsoft Exchange Transport service (on the local or remote Mailbox servers) and delivers them to a local mailbox database using RPC. Automatic Network Service Microsoft Exchange Active Directory Topology Required
Microsoft Exchange Mailbox Transport Submission MSExchangeSubmission Receives RPC messages from a local mailbox database, and submits them over SMTP to the Microsoft Exchange Transport service (on the local or remote Mailbox servers). Automatic Local System Microsoft Exchange Active Directory Topology Required
Microsoft Exchange Notifications Broker MSExchangeNotificationsBroker Provides Exchange notifications to local and remote Exchange processes. Automatic Local System Microsoft Exchange Active Directory Topology
• Net.TCP Port Sharing Service
Required
Microsoft Exchange POP3 MSExchangePOP3 Proxies POP3 client connections from the Client Access (frontend) services to the backend IMAP4 service on Mailbox servers. By default, this service isn't running, so POP3 clients can't connect to the Exchange server until this service is started. Manual Network Service Microsoft Exchange Active Directory Topology Optional
Microsoft Exchange POP3 Backend MSExchangePOP3BE Receives proxied POP3 client connections from the from the Client Access (frontend) POP3 service. By default, this service isn't running, so POP3 clients can't connect to the Exchange server until this service is started. Manual Network Service Microsoft Exchange Active Directory Topology Optional
Microsoft Exchange Replication Service MSExchangeRepl Provides replication functionality for mailbox databases in a database availability groups (DAGs). Automatic Local System Microsoft Exchange Active Directory Topology Required
Microsoft Exchange RPC Client Access MSExchangeRPC Manages client RPC connections for Exchange. Automatic Network Service Microsoft Exchange Active Directory Topology Required
Microsoft Exchange Search MSExchangeFastSearch Provides indexing of mailbox content, which improves the performance of content search. Automatic Local System Microsoft Exchange Active Directory Topology Required
Microsoft Exchange Search Host Controller HostControllerService Provides deployment and management services for applications on the local Exchange server. Automatic Local System HTTP Service Requirerd
Microsoft Exchange Server Extension for Windows Server Backup WSBExchange Enables Windows Server Backup to back and restore Exchange server data. Manual Local System None Optional
Microsoft Exchange Service Host MSExchangeServiceHost Provides a service host for Exchange components that don't have their own services. Automatic Local System Microsoft Exchange Active Directory Topology Required
Microsoft Exchange Throttling MSExchangeThrottling Provides user workload management that limits the rate of user operations (formerly known as user throttling). Automatic Network Service Microsoft Exchange Active Directory Topology Required
Microsoft Exchange Transport MSExchangeTransport Provides SMTP server and transport stack. Automatic Network Service Microsoft Exchange Active Directory Topology
• Microsoft Filtering Management Service
Required
Microsoft Exchange Transport Log Search MSExchangeTransportLogSearch Provides remote search capability for transport log files (for example, message tracking). Automatic Local System Microsoft Exchange Active Directory Topology Optional
Microsoft Exchange Unified Messaging (Exchange 2016 only) MSExchangeUM Provides Unified Messaging (UM) features: allows voice and fax messages to be stored in Exchange 2016 and gives users telephone access to email, voice mail, calendar, contacts, or an auto attendant. If this service is stopped, Unified Messaging isn't available.
If you don't use UM in Exchang 2016, you can disable this service.
Automatic Local System • CNG Key Isolation
• Microsoft Exchange Active Directory Topology
Optional
Microsoft Exchange Unified Messaging Call Router (Exchange 2016 only) MSExchangeUMCR Redirects UM client connections from the Client Access (frontend) services to the backend Unified Messaging service on Exchange 2016 Mailbox servers.
If you don't use UM in Exchange 2016, you can disable this service.
Automatic Local System • CNG Key Isolation
• Microsoft Exchange Active Directory Topology
Optional

Exchange services on Edge Transport servers

The following table describes the Exchange services that are installed on Edge Transport servers.

Service name Service short name Description Default startup type Security context Dependencies Required or optional
Microsoft Exchange ADAM ADAM_MSExchange Stores configuration data and recipient data on the Edge Transport server. This service represents the named instance of the Active Directory Lightweight Directory Services (AD LDS) that's automatically created by Exchange Setup. Automatic Network Service COM+ Event System Required
Microsoft Exchange Anti-spam Update MSExchangeAntispamUpdate Provides Exchange SmartScreen spam definition updates.
Note: In November, 2016, Microsoft stopped producing spam definition updates for the SmartScreen filters in Exchange and Outlook. The existing SmartScreen spam definitions were left in place, but their effectiveness will likely degrade over time. For more information, see Deprecating support for SmartScreen in Outlook and Exchange.
Automatic Local System Microsoft Exchange ADAM Optional
Microsoft Exchange Credential Service MSExchangeEdgeCredential Monitors credential changes in Active Directory Lightweight Directory Services (AD LDS) and installs the changes on the Edge Transport server. Automatic Local System Microsoft Exchange ADAM Required
Microsoft Exchange Diagnostics MSExchangeDiagnostics Provides an agent that monitors Exchange server health. Automatic Local System None Required
Microsoft Exchange Health Manager MSExchangeHM Part of managed availability that monitors the health of key components on the Exchange server. Automatic Local System • Windows Event Log
• Windows Management Instrumentation
Required
Microsoft Exchange Health Manager Recovery MSExchangeHMRecovery Part of managed availability that attempts to recover unhealthy components on the Exchange server. Automatic Local System Windows Event LogWindows Management Instrumentation Required
Microsoft Exchange Service Host MSExchangeServiceHost Provides a service host for Exchange components that don't have their own services. Automatic Local System Microsoft Exchange ADAM Required
Microsoft Exchange Transport MSExchangeTransport Provides SMTP server and transport stack. Automatic Network Service Microsoft Exchange ADAM Required
Microsoft Exchange Transport Log Search MSExchangeTransportLogSearch Provides remote search capability for transport log files (for example, message tracking). Automatic Local System Microsoft Exchange ADAM Optional