Email address spoofing

[Henry Kwan]

Alex Neuman van der Hans <alex <at> rtpty.com> writes:

> 3. Use a milter such as milter-null, which signs each outgoing  
> message, so that bounces that did not originate from your server are  
> not received. Leverage this with MailScanner's "Watermark" feature so  
> that your server doesn't accept or deliver spoofed messages.

Hi,

If you are already using the MailScanner "watermark" feature, is milter-null
needed?  Is there concern that the watermark can be spoofed?

Thanks.