If you’re using SmtpMail class in your projects, you may want to check out a new class in .NET 2.0 -- System.Net.SmtpClient.

 

This class allows you to send messages asynchronously and to receive a notification when the e-mail has been sent.  You can also cancel any pending asynchronous e-mails.  And there is less code to write! -- Settings such as a host to use, the default ‘from’ e-mail account, etc. can be defined in your application, web site or machine configuration file instead of setting object properties in code:

 

<configuration>

  <system.net>

    <mailSettings>

      <smtp deliveryMethod="network" from="somebody@contoso.com">

        <network

          host="smtphost.contoso.com"

          port="25"

          defaultCredentials="true"

        />

      </smtp>

    </mailSettings>

  </system.net>

</configuration>

 

 

The

SmtpClient client = new SmtpClient();

constructor will initializes the Host, Credentials, and Port properties for the new SmtpClient by using the settings in the application or machine configuration files, if they are available…

 

Source:  ms-help://MS.VSCC.v80/MS.MSDN.v80/MS.NETDEVFX.v20.en/dv_fxgenref/html/220b0329-e384-4e0c-86b4-0945ad17efd9.htm