If you blacklist a user or several users in Horde, it's possible to remove them and start getting e-mail from them again.

1. Ordered List Item- Log into Horde with your username and password.
2. Choose Options from the Menu Bar.
3. In the Mail Management Section, click on Filters.
4. Click on Edit your filter rules.
5. Select the rule(s) that you wish to remove.
6. Scroll to the bottom of the screen and click on the Delete button.

Click on the image above to see where the Filters section is located.