ASP.NET

HyperLink hypDetails = (HyperLink)e.Item.FindControl("hypDetails");

//namespace used

       //using System;
       //using System.Net.Mail;
       //using System.IO;
       MailMessage mm = new MailMessage("from_address", "to_address");


       byte[] atatchmentFile = FileUpload1.FileBytes;
       MemoryStream memStream = new MemoryStream(atatchmentFile);
       //attachment file form stream
       Attachment attachment = new Attachment(memStream, FileUpload1.FileName);
       mm.Attachments.Add(attachment);

       //smtp Host
       string smtpHost = "smtp.gmail.com";
       //smtp usename, add your username I userd gmail SMTP to send mail
       string userName = "your_username@gmail.com";
       //smtp passwords add your password
       string password = "your_password";

       //configuring smtp
       System.Net.Mail.SmtpClient mClient = new System.Net.Mail.SmtpClient();
       mClient.Port = 587;
       mClient.EnableSsl = true;
       mClient.UseDefaultCredentials = false;
       mClient.Credentials = new System.Net.NetworkCredential(userName, password);
       mClient.Host = smtpHost;
       mClient.DeliveryMethod = System.Net.Mail.SmtpDeliveryMethod.Network;

       //sending mail
       mClient.Send(mm);

benams wrote:

I HAVE TO use system.web.mail namespace.