How can I outsource XPhone Connect Mobile to a DMZ?
3. then perform the steps in the "Configuration - Mobile" paragraph from the following documentation article: https://help.c4b.com/de/xphone-connect-8/admin/#2950.htm
Note: The section "Customizing the URL for access by XPhone Mobile" refers to the main server, not the server in the DMZ.
Additionally, note that the ports must be enabled correctly:
If there are problems after the configuration and your partner needs assistance, he can contact our support. In most cases, the search for the cause will be easier if you are provided with a test user directly. Just send us the login name, the password, the mobile web address and a description of the misbehavior.