Overview of Exchange services on Exchange servers

Note

This article lists all the Exchange services and direct dependencies. There are other critical services deployed by the operating system, which may be indirectly used by the Exchange server. Microsoft doesn't test or recommend disabling various dependency services. These services shouldn't be disabled or stopped without proper functionality testing in the environment. If you stop these services and see negative effect on Exchange functionality, you must turn the services back on.

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 Emergency Mitigation	MSExchange Mitigation	Auto applies important security mitigations on Exchange Server to secure against known threats.	Automatic	Local System	IIS URL Rewrite Module	Required
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	Required
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 (Exchange 2016 only)	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	Required
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 Exchange 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