@Aron :I tried to get the same by using a web browser and i selected proceed anyway option then it takes me to the WSDL page.
I will assume that you are running your development server on your local dev machine. You should check the actual address that the IIS server is setup for. Open up the page in your web browser. You will have a page that asks you if you want to proceed anyway, DONT.
View server certificate.

Here is the GMail certificate. Notice the "issued to:". This means that the certificate is only for https://mail.google.com. If another server tried to use it for another address you would have the same error.
So you want to use whatever is in there as your https://{my issued to}/Webservice.asmx