Will Watermarking Stop Backscatter?

[Tom G. Christensen]

Koopmann, Jan-Peter wrote:
> To answer Daniel's original question: Yes, watermarking should stop most
> (if not all) backscatter that is out there. There are commercial
> programs out there as well (e.g. BarricadeMX) that use a very nifty
> E-Mail watermarking system as well. Give them a try. It is worth it.
> 
Stupid question perhaps, but how will it handle this case:
example.com enables watermarking using MailScanner
userA has emailaddress userA at example.com
On his homepc he configures his mail program to use userA at example.com as 
the From adress.
When he sends mail from home he uses his ISP smarthost and not the 
mailsystem at example.com
What happens when mail sent this way is bounced somewhere on the way?

-tgc