SMTP Email. Incorrect Port? No Port?

Hello experts!  I downloaded the sample project from here:
http://www.codeproject.com/KB/aspnet/SMTP_MailBySujithJohnThomas.aspx
 
When I debug it, I get this error: 'Format exception was unhandled by user code.  Input string was not in correct format.'
 
This line is highlighted green:
_mPort = Int32.Parse(ConfigurationManager.AppSettings["MailServerPort"].ToString());
 
 
I guess the port is incorrect.  Is that right?  Maybe the code is not linked to any port.  How do I make this work?
 
Thanks!
Ryan--
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