Notify users on plone states change

When a document is added to a folder how do you notify the reviewer that a file is added? Also when the reviewer send back or retract a file how do i notify the contributor that the file in retracted.. i tried content rules and it have not help.

If there are plugin which can help please suggest them.

Im using plone 4.3.6(4310) under python 2.7

there are 2 ways of solving this: the first one is related with a portlet that is shown only to users with role Reviewer when there is content in the state Pending review. this portlet i available in the default list and, IIRC, it's already assigned to members of the Reviewers group

another option is to create a content rule to send a message to a group of users every time a workflow state is changed.