An Exchange 2000/2003 mail-enabled public folder may have multiple SMTP addresses assosiated with it. For example, public folder named PubFolder has PubFolder@company.com primary SMTP address and PublicFolder@company.com secondary SMTP address. As Outlook always resolves both SMTP addresses to the name of this public folder, there is no way to see what address the message was originally sent to. The only known workaround is looking through message envelope headers (open a message > View > Options...).
WhichAddressPF for Exchange 2000/2003 application allows user to see which address the message was originally sent to.
The application is an Exchange store event sink.