help with email spam

i am getting at least 12 spam emails every day  from different hotmail email addresses.  i have tried to filter each one in the email  filter options but they still get through.  they just change the name before @hotmail.com. i made a filter rule to block each one.  then i make the condition from sender, and insert the email address in the box then i make the action as discard.   how else can i block emails? please help me with this problem.