Spam blocking

Up until I month ago I got virtually no spam in my gmail account.  Next thing I noticed I started receiving more each day.

 

I have religiously entered the addresses I receive in the block setting that Norton makes available.  Why do they continue to get through?

 

Thank you.

Up until I month ago I got virtually no spam in my gmail account.  Next thing I noticed I started receiving more each day.

 

I have religiously entered the addresses I receive in the block setting that Norton makes available.  Why do they continue to get through?

 

Thank you.