The Feedback Module is one that comes with the core DNN framework and can be used to get feedback from users about something on your website. In its most generic form, it can be used to provide a means by which a user on your website can ask you a question about anything.
This module has been in existence since the early days of Dotnetnuke (version 2x) and has steadily been upgraded with newer versions of DotNetNuke.
Feature List

• Feedback posted by users is sent to an email address and is also saved to a table in your database.
• Multiple Portals supported - for example on a site with multiple portals, users are not allowed to see Feedback that does not belong to that particular Portal (new in version 4.4.1)
• Multiple options for Subjects - users can be allowed to enter any subject for the email that is generated when a feedback is entered or the administrator can setup a subject from the administrative side which will be sent as the subject of the email for the feedback.
• Subject fields can now be presented to the user as a dropdown list and is handled similar to categories (new in version 4.4.1)
• Feedback can be grouped into categories and this can be used to setup different View Feedback Comment controls which show feedback based on a specific category.
• Feedback can be moderated - this means that any feedback that has been submitted will not be appear in the view feedback section till a Moderator has approved the post.
• Email field to be validated before form is submitted to check for valid email addresses. (new in version 4.4.1)
• Categories and Subjects can now be configured separately and has been migrated over from the generic Lists section of DotNetNuke which can only be administered by the Host. Site Administrators can now administer the Categories/Subjects at the module level. (new in version 4.4.1)
• Categories and Subjects are set at the Portal Level - i.e. multiple Portals will have separate Categories and Subjects.(new in version 4.4.1)

RoadMap (Future Versions)
 

• Track user statistics such as browser, IP address etc.
• Ability to create multiple fields on the feedback form so that the Site Administrator can setup different questions which can be answered besides the generic one currently supported.
• Ability to configure the View Feedback comments section and display different items. (new in version 4.4.2)
• Ability to configure Moderation by roles so that different people besides the Site Administrator can approve/publish feedback comments.  (new in version 4.4.2)
• Ability to delete unwanted feedback posts- previously user could only archive posts. (new in version 4.4.2)
• Ability to setup categories as email addresses. Once these are setup as email addreses, the feedback submitted can go to multiple email addresses if the user chooses the specific category. (new in version 4.4.2)
• Name of the sender is being saved with the feedback submitted.(new in version 4.4.2)