System.Net.Mail and multiple addresses

I have small project (C#, Visual Studio 2005, .NET 2.0) that runs a SQL stored procedure and creates an e-mail from the result set.  The "To," and "CC" fields are populated from the results.  My procedure will only return a single "To" addressee but there can be multiple CC's.  The stored proc is written to concatenate them all into a single string, e.g. "john.smith@xyz.com; jane.smith@xyz.com;...." etc.  So..... in my project I am using System.Net.Mail.  When I try to code "myMessage.CC.Add(read.GetString(3))" I get the following error:
The specified string is not in the form required for an e-mail address.In .NET 1.1 using System.Web.Mail this worked just fine.  The change to System.Net.Mail resulted in this error.

I really can't modify the stored procedure so I need to find a ...