FIREWALL AND ANTI-SPAM NOT FILTERING OUT ONE EMAIL ADDRESS

I use Norton Internet Security and MS Outlook.  I have tried to block and email from this company: "Houseology Design Team <designteam@houseology-email.com> "  and while it is in the blocked list, it keeps getting through using exactly the same email address as shown.  The other 'blocked' email addresses remain blocked, not this one. Any ideas, please?