Follow the procedure below:

Step 1: Provide your Microsoft Office 365 Global Administrator credentials to grant Cloud App Security the permission to use the Exchange Web Service Managed API for quarantine Management.

1. Access your Trend Micro Cloud App Security Console. Make sure to use an account with admin privilege.
2. Click Add Service Account or click on the tick box next to Exchange Online.

   

3. After you have been redirected, choose Exchange Online as the service:

   

4. Once you have chosen the service, click the link indicated in the pop-up window:

   

5. This will redirect you to the login page for your Microsoft Account. Take note that you need to login using your Global Admin Account for this step:

   

6. Read the terms and grant the permission required by clicking Accept:

   

7. After accepting the terms, you will be redirected back to the Cloud App Console. Verify that there should be a green check mark beside Step 1.

   

Step 2: Grant Cloud App Security the permission to use the Graph API to access all mailboxes.

1. Follow the link in Step 2 from the pop-up window. This will again prompt you log in to your Microsoft Account. Similar to Step 1, this process will ask your permission to grant Trend Micro Cloud App Security to get access to the specified resources as indicated below:

   

2. Once you click Accept and there were no errors encountered, you should see a window just like the image below:

   

Step 3: Synchronize all users and groups.

1. After closing the window, Step 2 should already be complete and you should see 2 green check marks on your console:

   

2. To protect all users, select Synchronize all user and groups and click Submit. Once complete, you should see Exchange Online checked on your console: