First of all you have to initiate the process. To do that you could use a Timer in your application or use Windows Scheduled Tasks to run your app, perhaps with a special commandline argument, at regular intervals.

As for sending the report, email functionality is provided in the System.Net.Mail namespace, mainly via the MailMessage and SmtpClient classes. There are lots of examples around of their use, so you should start by checking those out and playing around a bit until you find what works for your situation. You can include HTML in the body of the email if you like or you can add attachments. When you look for examples, just make sure that they are for System.Net.Mail and not the obsolete System.Web.Mail.