Unsubscribe from email messages or block messages in Outlook 365: Open the company email in its own window (double click on it) then scroll down to the end of the email and look for the ‘unsubscribe’ link (often in small text and underlined). Click on it to open the Unsubscribe webpage then confirm as required. To block an annoying email sender that does not offer this, in the Delete section of the ribbon, select Junk and choose Block Sender. You can block or unblock a sender anytime. Select Junk ❯ Junk E-mail Options. Choose the Safe Senders or Blocked Senders tab and make your changes