Did you take care of necessary configurations on Siteminder Policyserver to protect the TEWS url ? like creating realm and adding right user/group for access ?
/iam/im/TEWS6/prodsite
All the required realm/policies are created automatically while importing IME, If TEWS config was in-place in the environment-settings.xml file. if not, you will need create necessary configurations in Siteminder in order to protect your TEWS url