Postfix (email server) rebuild change default config?

Hey all,
Anyway to change default rebuild mail server config specifically for postfix/main.cf?
Everytime I rebuilt mail server it goes back to defaults(postfix/main.cf) and I lose my specific settings.

thanks

Yes, you should not rebuild the mail server more than once. It must be build and works fine.
Also, you can backup the configs and restore them once it rebuilt.