Customizable controls provided by a messaging application for performing selected actions

Technologies are described herein for providing users of a messaging application with controls that perform one or more selected actions with a message. Any number of default custom action controls may be displayed in a gallery. The selection of a custom action control performs various actions to an active message. New custom action controls may be created and existing controls modified to provide any number of desired actions. Dialogs provide user-friendly interfaces that allow a user to assign the desired functionality to a custom action control. The custom action controls may be organized into groups and shared between messaging applications and computers.