Force Exchange to send email outside

Hi JHNN3791 ,

You can create as the following.

1. Connect to Exchange Online PowerShell.
2. Create the Distribution List (DL):
   New-DistributionGroup -Name "NotMigratedUsers"
3. Add All Users to this DL.
4. Create the Connector:
   $result = New-OutboundConnector -Name "OnPremConnector" -ConnectorType OnPremises -SmartHosts "<fill smart host to source environment>" -UseMXRecord $false -IsTransportRuleScoped $true
   • -SmartHosts entry needs to be set to the URL or IP Address of the Source environment server.
5. Create Rule:
   $result = New-TransportRule -Name "Pilot" -SentToMemberOf "NotMigratedUsers" -RouteMessageOutboundConnector "OnPremConnector"

When a user is fully migrated, remove the user from the DL, and they will receive their email in their own Office 365 mailbox.