spam blocker

NIS spam blocker refuses to recognize Verizon's e-mail ports, which are nonstandard. They are Port 995 for POP3 and Port 465 for SMTP.. I get an error message saying they are used by "other programs." Verizon forces its users to use these ports, and without the ability to filter them for spam the NIS e-mail component is useless to me. What's the solution?