Identifying Emails from External Senders in Outlook [CHK-1023]
Outlook provides an option to label emails from external senders with a visible tag and warning message. This feature is not enabled by default.
Rationale
Labeling emails from external senders helps users recognize the origin of a message, making it easier to identify potential spam and phishing emails.
Fix
An automated fix is available through Attic. You can accept this fix via a ticket in Attic.
To fix it yourself:
-
Connect to Exchange Online using
Connect-ExchangeOnline. -
Run the following command to enable external email labeling:
Set-ExternalInOutlook -Enabled $true
Impact
This feature only works in Outlook. Other email programs or apps may not display the feature. Emails already present in the mailbox will not be retroactively labeled; only new emails received after the feature is enabled will be labeled. Any Mailflow rules that also provide external messages with a disclaimer or part in the subject must be disabled to prevent double labeling.
After activation of the feature, users on different systems will see the following features appear in Outlook, which can take 24-48 hours.