Manually Configuring the SMTP Email Server in Microsoft Windows

Updated June 15, 2010
Iron Speed Designer V7.0 and later

Configure these components to enable email server authentication on your system:

  1. Your application’s Web.config file.

  2. SMTP server on your system to allow relaying to itself.

Configuring Web.config

Step 1:  Locate your application’s Web.Config file, e.g.:


Step 2:  In Web.Config, modify the following line:


     <smtp from="">

          <network host="localhost" port="25" />



Replace “localhost” with either (a) your machine’s name or (b) the fully qualified domain name of your machine, e.g. computer or  Specify the port number and the “from” address as appropriate.

The mailSettings section in the Web.config is part of standard Microsoft .NET Framework settings.  More information about the various options available within the mailSettings section is available from the MSDN website at:

Modifying your SMTP Server Configuration

By default, the Windows SMTP server does not allow relaying.  In order for your application to send emails, you must enable relaying to the computer itself.  This solution opens up relaying to the local server only, so it is not open to everyone.  The is a local non-routable address that designates the machine you are using.

Step 1:  Open the Microsoft IIS Console

Start -> Settings -> Control Panel -> Administrative Tools -> Internet Information Services

Step 2:  On the left pane of the Microsoft IIS Console, expand the computer icon.


Step 3:  Right-click on "Default SMTP Virtual Server" and select Properties.


Step 4:  In the Properties dialog, select the Access Tab.


Step 5:  Select “Relay...”.


Step 6:  In the Relay Restriction dialog, add the IP Address of your system.  Make sure the "Only the list below" option is selected.  This will effectively allow your machine to communicate with its own SMTP server so emails can be sent.


Step 7:  Click OK to accept the changes.


Step 8:  Click OK until you've closed all the dialogs.

Your application can now send emails.

See Also

Configuring an Email Server Connection