I am also receiving more spam, which started around the same time as the complaints in this thread. At first it was 1-2 per day and it seemed someone was trying out ways to get around the Cox spam filters. They have succeeded and I now get at least 10 per day.
This is NOT a case of my giving out my Cox email addresses to the wrong company, because I rarely give it out. I have a separate domain registered to myself and use that for email, and my Cox email address is rarely used anymore. In my Cox spam messages I can see it is just someone randomly guessing at email addresses, such as:
user1 at cox.net
userabc at cox.net
user123 at cox.net
It seems any decent email filter should be able to detect and block these.
Ironically, my firewall sent me email from my own registered domain last night to my Cox email account, and it allowed two messages before Cox blocked the third one as spam. Since this exact setup has worked for the last two years, Cox must be making more changes to their spam filter.