Instructions on how modify edit your blacklist to block email address or domains.
Instructions
1 - Go to https://quarantine.hdcloud.co.uk
2 - Sign in with your email credentials. (Which you have set up previously through this guide: First Time Logging onto Email Filtering)
3 - Click on Sender blacklist in the menu
4 - Put in the domain or email address in the box highlighted. Then add
5 - Once added you get a confirmation and be able to see it listed