如何在。net 3.5中发送返回路径的邮件

Can any one guide me on how i can send emails with a return path in ASP.net 3.5 / C# 3.5. I know this was possible few years back but now due to spoofing issues this is not possible. I have been looking on internet but no use. I want the emails if bounced, should reach my bounce mail box, which could be like [email protected] any one guide me on how i can send emails w