SDN based e-mail denial source suppression system and suppression method thereof

The invention discloses an SDN based e-mail denial source suppression system and a suppression method thereof. The SDN based e-mail denial source suppression system includes a data plane, a forwarding plane and a control plane, wherein the data plane follows the traditional e-mail interactions of SMTP and POP3 in implementation and includes an SMTP client-side, an SMTP server-side, a POP3 client-side and a POP3 server-side; the control plane forms an e-mail denial control strategy based on previous e-mail interaction behaviors from the data plane and includes a behavior evidence obtaining module, a denial detection module, a denial evaluation module, a denial prediction module and a suppression strategy forming module; the forwarding plane forms a flow table according to a denial suppression strategy from the control plane, conducts forwarding control on the current e-mail interactions occurred on the data plane based on the flow table and includes a flow table calculation module and a forwarding processing m