Wing FTP Software

Hello,

i want to create multiple Domains and want them to use the same Ports.
For example:

Domain 1 has Users with privileges for http/https access and ftp. So the Listeners on Domain 1 have to run on Port 80, 443 and 21.
Domain 2 has Users only with privileges for ftp. So there i also have to enable the listener for FTP on port 21.

If i do so, the listener on Domain 2 can't start because of the ftp listener from Domain 1.

Is there a way to build a configuration like this, witch multiple Domains listening on the same ports for the same Protocols?
We have relative huge amount of different customers an we don't want to configure for each customer different ports.

Thanks in advance for your answers.
Best Regards
Philipp

Domain is just like a virtual server, so different domains must be separated by different ports (or different IP addresses).