Hi,
I have some confusion here. Im using yii-mail extension. But i have put all the script in protected/component directory. I have configures main.php and run well tested.
I wonder if it suppose to be in protected/extension directory? When should i use extension and when i should use component?
Thank you.
As far as I know, there’s no strict rule on that.
I think you can do it as you like.
Personally I use this rule:
component … application specific libraries.
extension … common libraries that I use in 2 or more apps.
And the entries in the extension directory are the symbolic links to those in my common library directory.
This rule made my source code version controlling much easier. 
Owh thanks for the tips softark!