Cloudmark Server Edition Online Help
The Connection tab is where you enter the settings that connect CSE service to the Cloudmark service.
This is the recommended setting and will yield the fastest connection speeds. If this port is not available to you, select “Port 80 over HTTP” instead.
Check this box if you use an HTTP proxy on your network and use port 80 as your Connection to Cloudmark Services.
Specify an IP address or hostname in the Address field and a port number in the Port field. The native Cloudmark Global Threat Network protocol is encapsulated in HTTP requests to comply with the HTTP 1.0 specification.
It is normally not necessary to enable DNS proxy support because Cloudmark Server Edition automatically switches to IP-based discovery mode to connect to the Cloudmark Global Threat Network.
If you experience “Unable to connect” errors, check Enable DNS Proxy Support and type in an Alternate Discovery Server IP address in the text box. The IP address is available here: https://www.cloudmark.com/en/knowledgebase/cloudmark-server-edition/Where-are-Cloudmarks-alternate-discovery-servers.