diff --git a/powershell/ServerSideSync/Grant-SssGraphApplicationPermissions.ps1 b/powershell/ServerSideSync/Grant-SssGraphApplicationPermissions.ps1
new file mode 100644
index 000000000..c3ad06ea3
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+++ b/powershell/ServerSideSync/Grant-SssGraphApplicationPermissions.ps1
@@ -0,0 +1,279 @@
+<#
+.SYNOPSIS
+Configures and grants consent for all Microsoft Graph application permissions
+required for synching emails from Exchange online mailboxes into another Tenant's dataverse.
+
+.DESCRIPTION
+Adds the complete Graph application-permission set to an existing Microsoft
+Entra app registration, preserves its other API permissions, and grants the
+corresponding app roles to its enterprise application.
+
+The script grants Mail.ReadWrite, Mail.Send, Calendars.ReadWrite,
+Contacts.ReadWrite, MailboxSettings.ReadWrite, Tasks.ReadWrite.All,
+Chat.Read.All, OnlineMeetings.ReadWrite.All, CallRecords.Read.All,
+MailboxConfigItem.ReadWrite, and User.Read.All. There are no workload switches.
+
+PreRequisites:
+1. Install Microsoft Graph PowerShell:
+   Install-Module Microsoft.Graph -Scope CurrentUser
+2. Sign in with an activated Global
+   Administrator role.
+3. Confirm that the application is already created in the MSFT tenant.
+
+Use -WhatIf first to review the proposed changes. The script prompts for
+confirmation before changing the app registration and before granting each
+permission. Every run writes a timestamped PowerShell transcript under the
+same directory as this script.
+
+.PARAMETER TenantId
+The Microsoft Entra tenant ID containing the app registration and Exchange
+Online mailboxes.
+
+.PARAMETER ClientId
+The Application (client) ID of the existing cross-tenant SSS app registration.
+
+.EXAMPLE
+.\Grant-SssGraphApplicationPermissions.ps1 `
+    -TenantId "11111111-2222-3333-4444-555555555555" `
+    -ClientId "aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee" `
+    -WhatIf
+
+Previews every proposed app-registration and consent change without applying
+it.
+
+.EXAMPLE
+.\Grant-SssGraphApplicationPermissions.ps1 `
+    -TenantId "11111111-2222-3333-4444-555555555555" `
+    -ClientId "aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee"
+
+Connects to Microsoft Graph, configures all required application permissions,
+prompts for confirmation, grants administrator consent, and displays the final
+consent state.
+
+.NOTES
+This script doesn't create the app registration, create credentials, configure
+Exchange Application RBAC, or deploy Dynamics 365 App for Outlook.
+#>
+
+[CmdletBinding(SupportsShouldProcess, ConfirmImpact = "High")]
+param(
+    [Parameter(Mandatory)]
+    [guid]$TenantId,
+
+    [Parameter(Mandatory)]
+    [guid]$ClientId
+)
+
+$ErrorActionPreference = "Stop"
+$transcriptTimestamp = (Get-Date).ToUniversalTime().ToString("yyyyMMdd-HHmmss")
+$transcriptPath = Join-Path $PSScriptRoot (
+    "Grant-SssGraphApplicationPermissions-{0}-{1}.log" -f
+        $transcriptTimestamp,
+        $PID
+)
+
+Start-Transcript -Path $transcriptPath -IncludeInvocationHeader
+Write-Host "Transcript: $transcriptPath"
+
+try {
+$graphAppId = "00000003-0000-0000-c000-000000000000"
+$requiredPermissions = @(
+    "Mail.ReadWrite"
+    "Mail.Send"
+    "Calendars.ReadWrite"
+    "Contacts.ReadWrite"
+    "MailboxSettings.ReadWrite"
+    "Tasks.ReadWrite.All"
+    "Chat.Read.All"
+    "OnlineMeetings.ReadWrite.All"
+    "CallRecords.Read.All"
+    "MailboxConfigItem.ReadWrite"
+    "User.Read.All"
+)
+
+$requiredCommands = @(
+    "Connect-MgGraph"
+    "Get-MgApplication"
+    "Update-MgApplication"
+    "Get-MgServicePrincipal"
+    "Get-MgServicePrincipalAppRoleAssignment"
+    "New-MgServicePrincipalAppRoleAssignment"
+)
+
+$missingCommands = $requiredCommands | Where-Object {
+    -not (Get-Command $_ -ErrorAction SilentlyContinue)
+}
+
+if ($missingCommands) {
+    throw @"
+Microsoft Graph PowerShell is required. Install it, then rerun this script:
+
+Install-Module Microsoft.Graph -Scope CurrentUser
+
+Missing commands: $($missingCommands -join ", ")
+"@
+}
+
+Connect-MgGraph `
+    -TenantId $TenantId `
+    -Scopes "Application.ReadWrite.All", "AppRoleAssignment.ReadWrite.All" `
+    -NoWelcome
+
+$context = Get-MgContext
+if ($context.TenantId -ne "$TenantId") {
+    throw "Connected to tenant '$($context.TenantId)', but '$TenantId' was requested."
+}
+
+$application = @(
+    Get-MgApplication `
+        -Filter "appId eq '$ClientId'" `
+        -Property "id,appId,displayName,requiredResourceAccess"
+)
+if ($application.Count -ne 1) {
+    throw "Expected one app registration with client ID '$ClientId'; found $($application.Count)."
+}
+$application = $application[0]
+
+$clientServicePrincipal = @(
+    Get-MgServicePrincipal `
+        -Filter "appId eq '$ClientId'" `
+        -Property "id,appId,displayName"
+)
+if ($clientServicePrincipal.Count -ne 1) {
+    throw "Expected one enterprise application with client ID '$ClientId'; found $($clientServicePrincipal.Count)."
+}
+$clientServicePrincipal = $clientServicePrincipal[0]
+
+$graphServicePrincipal = @(
+    Get-MgServicePrincipal `
+        -Filter "appId eq '$graphAppId'" `
+        -Property "id,appId,displayName,appRoles"
+)
+if ($graphServicePrincipal.Count -ne 1) {
+    throw "Expected one Microsoft Graph service principal; found $($graphServicePrincipal.Count)."
+}
+$graphServicePrincipal = $graphServicePrincipal[0]
+
+$resolvedRoles = foreach ($permission in $requiredPermissions) {
+    $matches = @(
+        $graphServicePrincipal.AppRoles | Where-Object {
+            $_.Value -eq $permission -and
+            $_.IsEnabled -and
+            $_.AllowedMemberTypes -contains "Application"
+        }
+    )
+
+    if ($matches.Count -ne 1) {
+        throw "Could not uniquely resolve the Microsoft Graph application permission '$permission'."
+    }
+
+    $matches[0]
+}
+
+$requiredResourceAccess = @(
+    foreach ($resource in $application.RequiredResourceAccess) {
+        if ($resource.ResourceAppId -ne $graphAppId) {
+            @{
+                ResourceAppId  = $resource.ResourceAppId
+                ResourceAccess = @(
+                    foreach ($access in $resource.ResourceAccess) {
+                        @{ Id = $access.Id; Type = $access.Type }
+                    }
+                )
+            }
+        }
+    }
+)
+
+$existingGraphAccess = @(
+    $application.RequiredResourceAccess |
+        Where-Object ResourceAppId -eq $graphAppId |
+        ForEach-Object ResourceAccess
+)
+$graphAccessByKey = @{}
+foreach ($access in $existingGraphAccess) {
+    $graphAccessByKey["$($access.Id):$($access.Type)"] = @{
+        Id   = $access.Id
+        Type = $access.Type
+    }
+}
+foreach ($role in $resolvedRoles) {
+    $graphAccessByKey["$($role.Id):Role"] = @{
+        Id   = $role.Id
+        Type = "Role"
+    }
+}
+
+$requiredResourceAccess += @{
+    ResourceAppId  = $graphAppId
+    ResourceAccess = @($graphAccessByKey.Values)
+}
+
+if ($PSCmdlet.ShouldProcess(
+        "$($application.DisplayName) ($ClientId)",
+        "Add requested Microsoft Graph application permissions"
+    )) {
+    Update-MgApplication `
+        -ApplicationId $application.Id `
+        -RequiredResourceAccess $requiredResourceAccess
+}
+
+$existingAssignments = @(
+    Get-MgServicePrincipalAppRoleAssignment `
+        -ServicePrincipalId $clientServicePrincipal.Id `
+        -All
+)
+$existingRoleIds = @(
+    $existingAssignments |
+        Where-Object ResourceId -eq $graphServicePrincipal.Id |
+        ForEach-Object { "$($_.AppRoleId)" }
+)
+
+foreach ($role in $resolvedRoles) {
+    if ("$($role.Id)" -in $existingRoleIds) {
+        Write-Host "Already granted: $($role.Value)"
+        continue
+    }
+
+    if ($PSCmdlet.ShouldProcess(
+            "$($clientServicePrincipal.DisplayName) ($ClientId)",
+            "Grant admin consent for Microsoft Graph application permission $($role.Value)"
+        )) {
+        $body = @{
+            PrincipalId = $clientServicePrincipal.Id
+            ResourceId  = $graphServicePrincipal.Id
+            AppRoleId    = $role.Id
+        }
+
+        New-MgServicePrincipalAppRoleAssignment `
+            -ServicePrincipalId $clientServicePrincipal.Id `
+            -BodyParameter $body | Out-Null
+        Write-Host "Granted: $($role.Value)"
+    }
+}
+
+$grantedRoleIds = @(
+    Get-MgServicePrincipalAppRoleAssignment `
+        -ServicePrincipalId $clientServicePrincipal.Id `
+        -All |
+        Where-Object ResourceId -eq $graphServicePrincipal.Id |
+        ForEach-Object { "$($_.AppRoleId)" }
+)
+
+$results = foreach ($role in $resolvedRoles) {
+    [pscustomobject]@{
+        Permission = $role.Value
+        Required   = $true
+        Consented  = ("$($role.Id)" -in $grantedRoleIds)
+    }
+}
+
+$results | Sort-Object Permission | Format-Table -AutoSize
+
+if ($results.Consented -contains $false -and -not $WhatIfPreference) {
+    throw "One or more permissions were not granted."
+}
+}
+finally {
+    Stop-Transcript
+}