Send email with attachment

public class EmailClass
{
public void SendMail(string mailFrom, string mailTo, string copyTo)
{
mail = new MailMessage();
mail.From = mailFrom;
mail.To = mailTo;
mail.Cc = copyTo;
mail.Subject = this.subject;
mail.Attachments.Add(new MailAttachment("c:\test.txt");

mail.Body = this.body;
mail.Priority = MailPriority.High;
mail.BodyFormat = MailFormat.html;
SmtpMail.SmtpServer = "172.16.0.23";

//You also need to add this code to send to someone else if file size
//is 0

if(new FileInfo(c:\test.txt)==0)
{
mail.To = "someoneElse@someoneelse.com";
}


SmtpMail.Send(mail);
}
}

The method should be in a class.
I think you should read up on some basic .Net programming
Email Notification Framework[^]

The error message implies that you have created an orphan method - one that is not part of a class or struct. If this is the complete code, then that is certainly the case. If so, you need to create a class with the above code as a member, then create an instance of the class and call it from Main. Alternatively, you could make the class containing the SendMail method static, then call the method without the need for instantiating it.

If there's more code to show, of course, I could be completely wrong; post some more! :)