How do you block unwanted email in the old Yahoo account?

How do I block a email from my yahoo account?

• There is a person with a gmail account is been harassing me trough my email and I would like to keep my email account but am tired getting those emails.

• Answer:

  Go into the email and Mark it as "spam". That way it'll go straight to the spam box. Or you could set up a filter (through the options tab) for all messages from that email address to go straight to the "trash" folder.