Mark Sender as Blocked in Outlook
Directly from your inbox, right-click on the email, select Junk -> select the desired option (Block Sender, Never Block Sender, etc.)
To manage your lists of safe and block senders/domains:
- Click on the Home tab in the ribbon.
- From the Delete group, select Junk and select Junk E-mail Options.
- Select the Blocked Senders tab.
- Click on the Add button.
- In the Add address or domain box, enter the full email address or the domain (@*******.com).
- Click on OK, and OK again.