System.Web.Mail and the pickup directory

Introduction

When you send e-mail using System.Web.Mail and the local SMTP server, you can avoid the roundtrip to the network and use the pickup directory.

The Code

You can easily update your existing code. For example take this:

eMail = new MailMessage();
eMail.BodyFormat = MailFormat.Text;
eMail.To = "recipients@codeproject.com";
eMail.Body = _Body;
eMail.From = _SendFrom;
SmtpMail.SmtpServer = "localhost";
SmtpMail.Send(eMail);

Just add two lines of code and you are done:

eMail = new MailMessage();
eMail.BodyFormat = MailFormat.Text;
eMail.To = "recipients@codeproject.com";
eMail.From = _SendFrom;
eMail.Body = _Body;
SmtpMail.SmtpServer = "localhost";
eMail.Fields["http://schemas.microsoft.com/cdo/configuration/sendusing"]  = 1;
eMail.Fields[
  "http://schemas.microsoft.com/cdo/configuration/smtpserverpickupdirectory"] = 
  "C:\\Inetpub\\mailroot\\Pickup";
SmtpMail.Send(eMail);

Conclusion

Especially if you want to send loads of e-mails, like in a newsletter application, you should keep this in mind.