Is your SSL certificate using the fully-qualified host as its NAME? In other words, instead of SERVER1 does it say SERVER1.domain.int instead? If not, you need to obtain a new certificate. The FQN is required in the certificate for Portal. From your screenshots, it looks like the certificate simply isn't trusted despite it being in the Trusted Certification Store. What happens when you request the Portal URL from a web browser directly? Does it load the Portal homepage? Are you challenged with a certificate warning in the browser?