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// graph-permissions · Mail

Mail.ReadBasic.AllMicrosoft Graph permission · High risk

Allows the app to read basic mail properties in all mailboxes without a signed-in user. Includes all properties except body, previewBody, attachments and any extended properties.

Application permission

High risk

Read basic mail in all mailboxes. Allows the app to read basic mail properties in all mailboxes without a signed-in user. Includes all properties except body, previewBody, attachments and any extended properties.

ID693c5e45-0940-467d-9b8a-1022fb9d42ef
ConsentAlways needs admin consent
RiskAs an application permission this reaches every user's data in the tenant, without anyone signed in.

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 "693c5e45-0940-467d-9b8a-1022fb9d42ef"

Which apps already have it?

powershell6 lines
# Apps that hold Mail.ReadBasic.All 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 "693c5e45-0940-467d-9b8a-1022fb9d42ef" |
    Select-Object PrincipalDisplayName, PrincipalId, CreatedDateTime

Other Mail permissions

Check every app in your tenant → Permission explainer

Sources