SmtpMail.SmtpServer = "IP_address"
to
SmtpMail.SmtpServer.Insert( 0, "IP_address")
where IP_address is the IP address of the SMTP server.
My officemate explained to me that this is a known issue of .NET 1.1 Framework. He said that the above-mentioned code will do as a workaround, but not all the time. Bummer.