- Open office.portal.com.
- Log in with the global administrator account.
- Go to admin center.Expand Admin centers and then click Exchange.
- In Exchange admin center dashboard, click rules under mail flow category.
- Click plus sign and then click ‘create a new rule’.
- Type the name of rule
- Choose ‘The sender is located’ from ‘Apply this rule’ drop down. When a new window opens, choose ‘Outside the organization’ and click OK.
- Choose ‘Delete the message without notifying anyone’ from ‘Do the following’ drop down.
- Click Save to save the new rule.
You are done!!