How to remove/omit mail-config

[Metatron]

Hy;

I'm supposed to host just the web-service of a domain, the mail-server and other services are on other machines. Is it possible to omit the setup of the mail-server for the given domain (by for example setting mail-users to -1)?

I also would like to know how to revert an existing configuration for not being used as the mails destination-server.

Google starts to give anoyingly meaningless results, also because I don't know the exact term of the configuration above. You may describe me which configs I would have to fix manualy though - if it's not possible through standard ispCP.

I'm using RC4