Block senders by right click
In Outlook, you can right click the email in the mailing list which you want to block the sender, then click Junk > Block Sender. Now the sender of selected email has been blocked.
Note:
1. This method does not support multi-select.
2. The block senders only take effect in current email account.
Block or unblock senders by using Junk function
If you want to block multiple senders at once time, you can use the Junk function in Outlook.
Block senders
1. Enable the email account you want to block specific senders, click Home > Junk > Junk E-mail Options.
2. In the Junk E-mails Options dialog, under Blocked Senders tab, click Add button.
3. Then in the Add address or domain dialog, type the sender address you want to block into the textbox.
4. Click OK, then repeat the above step 2 and 3 to add other sender addresses to the list box.
5. After adding all sender addresses you want to block, click OK to finish.
Unblock senders
1. if you want to unblock someone, go to the Junk E-mail Options dialog, under Save Senders tab, click Add button to add sender address you want to unblock into the Add address or domain dialog.
2. Repeat the above step to add all unblock sender addresses to the list.