Workflows ensure that items move through a predefined set of states before they become publishable. Sometimes, to meet business requirements, we might need to add or modify states, commands, or their respective actions.
Sitecore provides an e-mail action command that uses predefined parameters such as sender, recipient, and so on to send e-mails, which is not a practical way while working with multiple editors and reviewers. In real life, business users demand that when the reviewer rejects the changes done by the editor, an e-mail should be sent to the editor who did the changes with information regarding the item along with the reviewer's comments. In this recipe, we will achieve this requirement by creating a custom action using workflow APIs.
This recipe assumes that you are aware of how Sitecore workflow works. For a basic understanding, you can refer to Sitecore Workflow QuickStart Guide at http://goo.gl/7HSKqR.