Question regarding SA learn

[M�rio Gamito]

Hi,
I've created an account called [EMAIL PROTECTED] and told all my clients 
that when they receive a SPAM message not marked as such, to forward it 
 to that account.

Then, i thought of everyday runnig in crontab, something like:
53 23 * * * root /usr/bin/sa-learn --spam 
/home/vpopmail/domains/mydomain.com/spam/Maildir/new

But then, it came to my mind, that in this way, the e-mail addresses of 
my clients that forwards the messages will be caught in the SA learn fire.

Any ideias how to avoid that, or other way to make it right ?
Any help would be appreciated.
Warm regards,
M�rio Gamito