A hybrid shared mailbox is not syncing into Activate during the mailbox sync process.  The Activate_MailboxSync.log file shows that the mailbox has been found in Entra

but no Mailbox resource is being created in Activate.

The most likely cause of this issue will be the Azure Users sync.  If an Activate user cache entry that matches the mailbox's UPN is not found then the mailbox resource may not be created.  This can be determined by looking at the ADCache table (AzureID and AzureUPN columns) and checking whether the local AD account has an Entra ID cloud account mapped to it. 

To try and resolve this issue follow these steps:

In Activate Studio browse to Roles > System Roles > Azure Users.

Members OU Reference =     OU=Users,DC=

Confirm there is one Members parameter referencing OU=Users,DC=

,DC=onmicrosoft,DC=com.  There also may be another Members parameter referencing the local domain.

Run a full Azure Sync, this should be setup in the scheduler to run on a nightly basis.  To force a full sync during the next scheduled run:

Delete Resources/ActiveDirectory/External Directories/Azure/UserSync_Token

This may take some time depending on the size of the domain so it's recommended to run this outside of business hours.

After running these steps the AzureID and AzureUPN should now be present on the local AD entry in ADCache.  Running the Mailbox sync again now should import the missing mailboxes.

If you are still encountering issues then it could be the System Roles > Users role, ensure that the Members parameters include the OUs in which the on-prem mailbox accounts reside.  The on-prem mailbox accounts must exist in ADCache table for the mailbox resource to be created, so ensure the Users background sync is operating.  This can be found here:

=//System/Tasks/Background/MaintenanceScript

=//Resources/Schedulers/Nightly - License Statistics

If you've found this not be configured correctly, then enable the scheduler, once it has run then repeat the steps in Solution 1 to force a full Azure Sync.

Other Mailbox Errors

Troubleshooting Mailbox Sync

Microsoft’s cloud platform providing infrastructure, networking, storage, and application services. In Activate, it’s used as the hosting environment or for integration with Microsoft 365 and Entra ID services.

Azure

DotNetVersion

Microsoft Entra Connect (formerly Azure AD Connect) is a tool that syncs on-premises Active Directory identities with Microsoft Entra ID, enabling hybrid identity and seamless access to cloud resources.

Microsoft_Entra_Connect

Active Directory (AD) is Microsoft’s directory service that stores and manages user accounts, devices, and permissions, enabling secure authentication and centralized access control within a Windows network.

Active_Directory

ActivateJobService

ActivateAdministrator

SupportedPowerShellVersions

SupportedOSVersions

SupportedSQLVersions

Name that identifies the instance of Activate.  This is only used by Administrators and isn't displayed to end users.

instance_name

An installation type of Activate where there is no local domain connection, all authentication, authorisation and identity management is handled by Entra ID.

Cloud_Only

Microsoft Entra ID (formerly Azure Active Directory) is Microsoft’s cloud-based identity and access management service, providing secure authentication, user lifecycle management, and access control for Microsoft 365 and other apps.

Microsoft_Entra_ID

A software switch that enables or disables functionality at runtime without redeploying code. In Activate, they are configured under //Resources/Configuration/FeatureFlags.

feature_flag

Microsoft module for managing Exchange Online, using modern authentication and REST API–based cmdlets for faster, more reliable automation of mailboxes, compliance, and organisation settings.

EXO_V3_PowerShell_Module

An Organizational Unit (OU) is a container in Active Directory used to organise users, groups, computers, and other objects within a domain. OUs help structure resources logically and apply group policies for easier management and administration.

A User Type is a template in Activate that defines rules, attributes, and behaviours for a category of users (e.g., Employee, Contractor), ensuring consistent user account setup and configuration.

User_Type

A resource object in Activate representing a physical or virtual Exchange Server

Exchange_Server_Resource

Defines the object type that the resource will emulate or operate as.

Class_parameter

Clonesthe selected inherited parameter to make a local copy to override the value

Override

Runs the Activate Provisioning Server and performs actions across target systems.

Orchestrator_Account

A complete, immutable log of identity-related events, including provisioning actions, access approvals, and policy evaluations.

Audit_Trail

An integration module that enables Activate to read/write data from external systems (e.g., provisioning accounts in Azure AD).

Connector

A periodic process where managers or data owners validate that users still require their existing access — critical for compliance.

Access_Certification_and_Review

A user-initiated process to gain access to new systems or roles, often requiring manager or system owner approval.

Access_Request

Any downstream application or service where identities need access (e.g., Active Directory, Okta, Salesforce).

Target_System

The authoritative system from which identity data is imported (e.g., HRIS like Workday or SAP SuccessFactors).

Identity_Source

An access control model that uses user, resource, or environment attributes (e.g., department = "HR", location = "US") to make access decisions dynamically.

ABAC_Attribute-Based_Access_Control

An access control model where users receive permissions based on assigned roles. This model helps enforce least privilege.

RBAC_Role-Based_Access_Control

A collection of entitlements assigned based on a user’s job function or department. Roles simplify access management and are often tied to policies (e.g., "Finance Analyst Role").

Role

A specific access right or permission within a system (e.g., "Read-only access to Salesforce Reports"). Entitlements can be grouped into roles.

Entitlement

The removal or disabling of user accounts and access when they are no longer required — for example, when an employee leaves the organization.

Deprovisioning

The automated process of creating accounts and granting access to systems or applications based on a user’s role or attributes.

Provisioning

A digital representation of a user (employee, contractor, service account, etc.) within an organization. Each identity is typically linked to a unique identifier, such as an email address or employee ID.

Identity

This is the process of bringing on a new user

Onboarding

Hierarchical Role-Based Provisioning automates user access by assigning roles based on organisational structure, ensuring users inherit the correct permissions and resources aligned to their position or function.

Hierarchical_Role-Based_Provisioning

A group email address that automatically forwards messages to all its members, allowing you to send emails to multiple recipients at once.

Distribution_List

An expression is a conditional statement using Activate expression syntax.

expression

AzureProductName

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