The Search Emails screen allows you to search for emails that have been sent by the Online Bill Payment system. It will provide you with multiple filtering options for searching and allow you to sort the results by the date the mail was sent, who it was sent to or the subject of the mail.
The image below is what you will see when you first select the Search tab in the Client administration console for the Online Bill Payment system. At the top of the screen below the tabs it will display the options that were last selected for a search. This will change when you select new search criteria in the Filter.