It has been a long time since I have written a component that sends email.  In the .NET world, sending email has been made very easy and all the objects are defind under the System.Web.Mail namespace.  System.Web.Mail is a simple wrapper for the COM objects in cdonts.dll and cdosys.dll.

Following is a code snipped for sending email with an attachment:

   MailMessage MailMsg= new MailMessage();
   MailMsg.To = "sunitc@microsoft.com";
   MailMsg.From = "SWM_Test@sunitc.com";
   MailMsg.Subject = "[info] System.Wed.Mail Test Message";
   MailMsg.Body = "System.Web.Mail Body of the Message";
   // Create the attachment : enter the correct path to the file that is to be attached
   MailAttachment attachment = new MailAttachment("mypath\test.txt"); //create the attachment
   MailMsg.Attachments.Add( attachment );
   // Put in your real smtp server below
   SmtpMail.SmtpServer = "mySmtpServer";
   SmtpMail.Send( MailMsg);