I did a similar thing for my final year project.
I had a table in my database with all the users' email addresses, and another one with the set messages i wanted to display eg: "Your order number is :" and i would insert the order number from my app.
I used a stringbuilder so that the email would be written as one sentence. You can manipulate it however you want.
So, in my view layer, i had the following code in the user registration page (since an email is sent to confirm the registration:
using System.Net;
using System.Net.Mail;
public void CreateUser()
{
StringBuilder message = new StringBuilder();
message.Append(BC_GmailSender.GetMessage(13));
message.AppendLine(BC_GmailSender.GetMessage(8) + " " + cust_id);
message.AppendLine(BC_GmailSender.GetMessage(9) + " " + password);
NetworkCredential loginInfo = new NetworkCredential("your_email@gmail.com", "your_password");
MailMessage msg = new MailMessage();
msg.From = new MailAddress("your_email@gmail.com");
msg.To.Add(new MailAddress(email));
msg.Subject = "Whatever subject";
msg.Body = message.ToString();
msg.IsBodyHtml = true;
SmtpClient client = new SmtpClient("smtp.gmail.com");
client.EnableSsl = true;
client.UseDefaultCredentials = false;
client.Credentials = loginInfo;
client.Send(msg);
}