c# - Send mail using localhost SMTP

Question

I am trying to setup SMTP server on IIS for sending mails. The SMTP server is intended to be used by the ASP.NET code in C#.

I was previously using gmail smtp wherein i provided the smtp.gmail.com as host with secure port and my gmail uid/pwd. That worked fine. Here is the code used to do that.

SmtpClient smtpClient = new SmtpClient();
smtpClient.UseDefaultCredentials = false;
smtpClient.Host = "smtp.gmail.com";
smtpClient.Port = 587;
smtpClient.Credentials = new NetworkCredential(uname,pwd);
smtpClient.EnableSsl = true;
smtpClient.Send(mailMessage);

Now i am planning to use the localhost SMTP server on IIS, what values should i be giving for the parameters UseDefaultCredentials and Credentials. I will be assigning false to EnableSsl as it's over port 25.

Also, what could be the most simple SMTP virtual server configuration.

Answer 1

When you are using the local IIS SMTP service, set the DeliveryMethod to PickupDirectoryFromIis. For example:

  smtpClient.DeliveryMethod = SmtpDeliveryMethod.PickupDirectoryFromIis;

This totally bypasses the network layer, and writes the messages directly to disk. Its much faster than going through the chatty SMTP protocol.

When you using the above code, it means you can get rid of this part of your code:

smtpClient.UseDefaultCredentials = false;
smtpClient.Host = "smtp.gmail.com";
smtpClient.Port = 587;
smtpClient.Credentials = new NetworkCredential(uname,pwd);
smtpClient.EnableSsl = true;