Zoho Stop the Spam Mail

Zoho Stop the Spam Mail

What the H*** is going on with all the spam mail?  I get at least 40-50 spam emails a day.  I mark them as spam every time and still they are never ending.  I have added my email to a national do not email list, but I still get them.  I have other business email account with other organizations and NEVER get spam mail to those inboxes.  Is this why the service is free, because of all the spam?  If I continue to get this much spam each day, I will be forced to take my business elsewhere.