This web part processes forum unsubscription requests submitted by users and displays a confirmation message.

The web part can be used to create a forum unsubscription page with a custom design that will be used instead of the default system page.  The URL of such a page can be assigned to individual forum groups or forums through their Forum unsubscription URL property, or globally in Site Manager -> Settings -> Community -> Forums -> Forum unsubscription URL. Once assigned, the unsubscription link in the notifications for the given forums will lead to the page. There, the web part will automatically process the query string parameters and perform the required unsubscription.

Help URL: http://devnet.kentico.com/docs/webparts/index.html?ForumUnsubscription_overview.htm