You want to create a New inbound Connector
O365
Log into https://admin.exchange.microsoft.com/
Select Mailflow > Connector
And click add connector
Click from Your organization's email server
Click next
Give your connector a name
Click next
Select By verifying that the subject name on the certificate that the sending server uses to authenticate with Microsoft 365 matches this domain name.
add the Cloud Detector (SMTP Smarthost) URL that is indicated in the Adding a Sender Domain section. This value is the first 13 characters of the detector ID plus the domain ds.dlp.protect.broad.com.
For example: 12345678-abcd.ds.dlp.protect.broadcom.com.
Click next
For additional guides please see the "Getting Started with Data Loss Prevention"
To provide feedback please click on the "Feedback" link or send an email to "[email protected]"