Send Email With Attachment in asp.net

In this example i am going to describe how to send email with attachment in ASP.NET using fileUpload Control. I am saving the uploaded file into memory stream rather then saving it on server.And for this example i m using Gmail SMTP server to send mail, this code also works fine with any SMTP Server. For sending Email in ASP.NET , first of allwe need to add Syatem.Net.Mail namespace in code behind of aspx page.