Ensure email from external senders is identified.
exchange_external_email_tagging_enabled
Ensure that emails from external senders are identified using the native External tag experience in Outlook clients, which helps users recognize messages originating outside the organization.
Risk
If external email tagging is not enabled, users may be unable to quickly identify emails coming from outside the organization, increasing the risk of phishing or social engineering attacks.
Run this check with Prowler CLI
prowler m365 --checks exchange_external_email_tagging_enabled
Remediation
Set-ExternalInOutlook -Enabled $true
Enable the External tag for Outlook to help users visually identify emails from outside the organization.
Source Code
References
Resource Type
Exchange External Mail Tagging