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// graph-permissions · Mail

Mail.ReadMicrosoft Graph permission · High risk

Allows the app to read mail in all mailboxes without a signed-in user.

Application permission

High risk

Read mail in all mailboxes. Allows the app to read mail in all mailboxes without a signed-in user.

ID810c84a8-4a9e-49e6-bf7d-12d183f40d01
ConsentAlways needs admin consent
RiskAs an application permission this reaches every user's data in the tenant, without anyone signed in.

Delegated permission

Medium risk

Read user mail . Allows the app to read the signed-in user's mailbox.

ID570282fd-fa5c-430d-a7fd-fc8dc98a9dca
ConsentUsers can consent, if your consent settings allow it
RiskReads or changes the signed-in user's content, limited to what that user can access.

Least-privilege alternative

If you only need headers and metadata, use Mail.ReadBasic. For application permissions, limit which mailboxes the app can reach with Exchange Online RBAC for applications.

Grant it to an app

In the portal: App registrations › your app › API permissions › Add a permission › Microsoft Graph › Application permissions, then grant admin consent. Or with Graph PowerShell:

powershell5 lines
Connect-MgGraph -Scopes "Application.Read.All", "AppRoleAssignment.ReadWrite.All"
$graph = Get-MgServicePrincipal -Filter "appId eq '00000003-0000-0000-c000-000000000000'"
$app   = Get-MgServicePrincipal -Filter "appId eq '<your app's client id>'"
New-MgServicePrincipalAppRoleAssignment -ServicePrincipalId $app.Id `
    -PrincipalId $app.Id -ResourceId $graph.Id -AppRoleId "810c84a8-4a9e-49e6-bf7d-12d183f40d01"

Ask for it when signing in

Delegated permissions act as the signed-in user, so the app can never do more than that user can.

powershell1 line
Connect-MgGraph -Scopes "Mail.Read"

Which apps already have it?

powershell6 lines
# Apps that hold Mail.Read as an application permission
Connect-MgGraph -Scopes "Application.Read.All"
$graph = Get-MgServicePrincipal -Filter "appId eq '00000003-0000-0000-c000-000000000000'"
Get-MgServicePrincipalAppRoleAssignedTo -ServicePrincipalId $graph.Id -All |
    Where-Object AppRoleId -eq "810c84a8-4a9e-49e6-bf7d-12d183f40d01" |
    Select-Object PrincipalDisplayName, PrincipalId, CreatedDateTime
powershell6 lines
# Apps with delegated consent for Mail.Read
Connect-MgGraph -Scopes "Application.Read.All", "Directory.Read.All"
$graph = Get-MgServicePrincipal -Filter "appId eq '00000003-0000-0000-c000-000000000000'"
Get-MgOauth2PermissionGrant -All |
    Where-Object { $_.ResourceId -eq $graph.Id -and ($_.Scope -split " ") -contains "Mail.Read" } |
    Select-Object ClientId, ConsentType, PrincipalId

Other Mail permissions

Check every app in your tenant → Permission explainer

Sources