config.resources=mule-main-config.xml,mule-transports-config.xml
Using Side-by-Side Configuration Files
Side by side configurations are independent and require nothing specific to work except to let Mule know it should load them.
To do so, create a file named mule-deploy.properties in the same directory that contains your configuration files and add configuration similar to the following one, but of course with your configuration file names:
With this in place, Mule will know which configuration files it should load when deploying your application.
If you’re starting your application from Eclipse, go to the parameters screen of the "Run" configuration you use and select your files there.