Please let me tell each steps for following work.
Your certificate will expire on 01. February 2008.
IF YOU USE THIS SAPROUTER WITH SECURE NETWORK COMMUNICATION (NOT VPN)
THIS WILL MEAN THAT YOU CAN NO LONGER USE THIS SAPROUTER TO ESTABLISH A
CONNECTION TO THE SAP SUPPORT.
To prevent this we would like to urgently ask you to replace your
existing Certificate with a new one from the SAP Service Marketplace