Don't worry, you can still supply your script to everyone. MTA provides a server "registry" where server admins can store configuration such as login.
Even then, you could easilly provide a script which lacks the login details.
As for the issue of trust and people stealing your work (i know this isn't your problem, but for those who are wondering), the chances of someone ripping off your work and getting away with it are slim.
You mean you can communicate to the MTA server and asking settings and use that settings?
And CRC how does it work I searched on wikipedia and on the dutch part it was uncomplete and the english part I don't understand really good. But is it with a kind of pluggin?