Set-ExternalInOutlook -AllowList {} still tagging emails as External

Copper Contributor

After configured Set-ExternalInOutlook to true, I noticed emails sent using our primary SMTP domain from on premise apps to (Exchange Online),  are still being tagged with External. I added our primany SMTP domain to the AllowList, "" but they are still being tagged as External.


I was expected this would fix the issue but it has not. Is this expected behavior since it's using the same sub SMTP domain? 



2 Replies

Hi @K-ROD,


just wait. When I tested it,  after executing the commandlet the Allowlist behavior has been changed in 60 hours.


If you interested in GUI for "Set-ExternalInOutlook",  have a look at this.

Sorry, I forgot to mention it's been roughly a week now.