How many times do I have to Report Spam from a mail address to block all the mails from that address or send them all to spam? I have reported an email for spam about 7 times but Gmail shows new mails from that address as Important.
Gmail's spam filters aren't simply based on the Senders email address. And it is also dependent on other users flagging similar emails as spam. Gmail determines that a particular email is spam by seeing how the global gmail community sees that email.
If all this spam / unwanted messages are coming from a single email address then you can set up a filter to send all email from that sender to spam. Filters affect just your email account.
Are those mail ids in your addressbook? If then, remove those emails from your addressbook first.