How to block a sender in Outlook mailing:

(i) Mouse Right click on your mail which want to block. Than click to Junk and click to Block Sender.

(ii) Again mouse Right click on your mail which want to block. Than click to Junk and click to Junk E-mail Options... Give the tick mark on "Permanently delete suspected junk e-mail instead of moving it to the Junk E-mail folder" and click to OK to apply.

Video:

How to block a sender in Outlook mailing: