The "Block Address" is only of any use to block genuine email addresses that you do not want to receive emails from.
It is about as much use as a chocolate fireguard when it comes to blocking spam.
Most spam does not come from the email addresses that you see when you receive and email. The spammers often uses "spoofed" email addresses (see link about spoofing).
The spammers also constantly change their email addresses, which are often computer generated in order to avoid being blocked.
See link about spoofing:-
Email spoofing - Wikipedia
If you want to block a spammers email address, which is virtually a waste of time, you will need to find the genuine email address it is sent from and block that email address.
To find the genuine email address when logged onto your email account you should tick the box to the left of the email in your list of emails then go to the menu bar and click on "more" then "view source". It is the email address that you will find there that you need to block.
Once your email address is on the spammers list your email address will always get spam to a greater or lesser extent.
You should also never open a spam email as by doing so informs the spammer that they have found an active email account.
