To blacklist multiple contacts that you import from a .csv file:
1. Create a new list on the People page.
2. Open the Import from CSV dialog window and follow the procedure.
3. On the Review & Import step, select the list you have created.
4. Click Import. This action imports contacts from your .csv file to Reply.
5. Open the list with the imported contacts.
6. Select all contacts in the list.
7. In the More drop down menu, click Blacklist.
8. In the popup window, click Blacklist xxx contacts.