You can mark an email as junk, but, if you don't want to receive more emails from that email address, you will have to block the sender. 




From Office 365:


  1. Click on the gear to open the menu.
  2. Choose Mail from the My app settings section.
  3. Choose Block or allow from the Accounts section of the Options menu.
  4. Scroll down to the Blocked senders section.
  5. Add the email that you want to block in the field that says Enter a sender or domain here.
  6. Press the Save icon at the top of the page, then press the arrow in front of the Options menu to get back to your email.



From Outlook on your Windows computer:


  1. Right-click on the email that you want to block.
  2. Highlight Junk from the menu that pops up.
  3. Choose Block Sender from the menu that pops up.



From Outlook on your Mac computer:


  1. Right-click (or Control-click if you don't have a mouse with a right-click) on the email that you want to block.
  2. Highlight Junk Mail from the menu that pops up.
  3. Choose Block Sender from the menu that pops up.