Block email addresses in Hotmail -- or Outlook.com -- by adding them to the Blocked Senders list. Email from blocked senders is deleted immediately. Hotmail doesn't notify the owner of the email address when you add it to the Blocked Senders list, and you can remove addresses from the list at any time. Furthermore, you can block entire domains if you notice that all, or most, of their email addresses are used for spam purposes.
Log in to Hotmail, click the gear-shaped icon and select Options from the menu to display the Outlook Options page.
Click the Safe and Blocked Senders link in the Preventing Junk Emails section and then click the Blocked Senders link to manage the Blocked Senders list.
Type the email address you want to block into the Blocked Email Address or Domain field and click the Add to List button to block it.
To add an entire domain to the Blocked Senders list, type only the domain -- @sampledomain.com, for example -- into the field and click Add to List. Note that by blocking an entire domain, you may block legitimate email addresses.
Remove email addresses or domains from the Blocked Senders list by selecting them and clicking the Remove From List button. To select several items, hold Ctrl and click each email or domain.