Enviar

MailMessage theMailMessage = new MailMessage("from@email.com", "to@email.com");
theMailMessage.Body = "body email message here";
theMailMessage.Attachments.Add(new Attachment("pathToEmailAttachment"));
theMailMessage.Subject = "Subject here";
SmtpClient theClient = new SmtpClient("IP.Address.Of.Smtp");
theClient.UseDefaultCredentials = false;

System.Net.NetworkCredential theCredential = new System.Net.NetworkCredential("user@name.com", "password");

theClient.Credentials = theCredential;

theClient.Send(theMailMessage);