Background information:

We have managed package that is using the Api.Partner_Server_URL_210 to get the serverURL that can be used by the external system to call back into the Salesforce using Soap API.

This managed package is embedded within Opportunity page. We have enabled Partner portal through site.

Site is using the custom domain as "mycompany.secure.force.com"

Custom domain is not enabled for the org.

Working Scenario :

When the PRM portal user is logged from the Salesforce's contact page using "Login to Partner Portal",  user gets to the standard Partner portal page and navigates to the Opportunity page and clicks to view the managed packages's custom VF page. In this scenario VF get https://managepackagenamespace.na1.salesforce.com/XXXXXX/" as API.Partner_server_URL. Using this URL external system is able to connect back to Salesforce via Soap API and get the data.

Non-working Scenarion:



When the PRM portal user is logged from external facing site URL https://mycompany.secure.force.com/sitelogin page and then navigates to the Opportunity page and clicks to view the managed packages's custom VF page. In this scenario VF get https://mycompany.secure.force.com/XXXXXX/" as API.Partner_server_URL. Using this URL external system is NOT able to connect back to Salesforce via Soap API and get the data.

So question is does $API..Partner_server_URL suppose to return https://managepackagenamespace.na1.salesforce.com/XXXXXX/" value or Salesforce platform does not allow API calls to https://mycompany.secure.force.com/ URL.

Any help would be appreciated.

Thank you.