I see in the url the site is using port 2095. If you are using the http proxy in standard mode you can create a service for this port and add it to the "allowed target services" on the advanced tab of the http proxy. If you are not using the http proxy or it is in transparent mode create a service for this port and create a packet filter rule to allow this traffic. Since you say this is a new install please also check that you have created a NAT masq rule for your internal network and the external interface.
