External Sender Tagging
The question it answers: Is mail from outside the organisation tagged as External in Outlook, and which senders are exempt?
Business-email-compromise mail pretends to come from a colleague or the CEO. The ‘External’ tag in Outlook is the cheapest signal to users that it did not - and every exempted domain removes that signal.
At a glance
Section titled “At a glance”| Where in the app | Exchange Online › Mail Security Posture › External Sender Tagging |
| Workload | Exchange Online |
| Kind | Findings list · dashboard tile |
| Data | Read from Microsoft 365 when someone first opens it, then kept for the report cache lifetime (Settings > Data & cache, 1 hour unless changed). It reads through PowerShell (Exchange Online or SharePoint Online), so the first load takes longer than a Graph report. |
| Licence | Exchange Online. |
| Report id (API and MCP) | exchange.posture.external-tagging |
Columns
Section titled “Columns”| Column | Key | Type |
|---|---|---|
| Severity | Severity | Status |
| Area | Category | Text |
| Subject | Subject | Link |
| Setting | Setting | Text |
| Current value | Value | Text |
| Assessment | Finding | Text |
| Detail | Detail | Text |
| Date | When | Date |
| Count | Number | Number |
A findings list hides columns that no row fills. Severity is Critical, Serious, Warning, OK or Info; rows rated Critical, Serious or Warning need attention (Working with findings).
What it needs
Section titled “What it needs”Licence: Exchange Online.
Application permissions on the IntensiveReports app registration (all permissions):
| Permission | API | What it allows | Note |
|---|---|---|---|
Exchange.ManageAsApp | Office 365 Exchange Online | Manage Exchange As Application |
Data sources it reads
Get-ExternalInOutlook
Through the API and MCP
Section titled “Through the API and MCP”GET /ir-api/v1/reports/exchange.posture.external-tagging?size=100An AI assistant reads it with the MCP tool get_report and the id exchange.posture.external-tagging. The client needs the Read grant for Exchange Online. See Using the API.