Unable to set remote mx via api

I set up websites for clients using one cpanel-account for each client. I never use cpanel email, but instead the client always use the domain provider email services. When adding a domain via API I must manually set Email routing to "Remote", since "Auto" makes mails sent from local domain to local domain does not get sent. (Example PHP mail sends notification about new order to the admin of example.com to admin@example.com) So I try to change to remote mx via uapi: $this->callUAPI($this->cpaneluser, "Email", "set_always_accept", $parameters = array( "domain" => $domain, "mxcheck" => 'remote', ));
Does not work.... And with cpanel api2: $this->cpanel->callCpanelApi($this->cpaneluser, "Email", "setalwaysaccept", $parameters = array( "domain" => $domain, "mxcheck" => 'remote', "user" => $this->cpaneluser, ));
Does not work :( 1. Can I completely disable Local mail, so that ALL mail is handeled by remote mx? (All = all domains and accounts on the server) 2. Or: Can I fix the above api-calls so that they work? 3. Or: can I run a cronjob to update all domains to set mail routing to "Remote" instead of "Auto"