High Scoring Spam Rules Issue

[Rob Poe]

  I have a user who insists on getting all email (even spam).  He's 
finally relented on letting me at least TAG them as {spam}, but here's 
an issue I'm having.

I made a rule file for high scoring spam actions.

In the rule file, I put

To: user1 at domain.com deliver
FromOrTo: default store

That works swimmingly.  Here's the problem.  Say the spam is addressed 
to user1 at domain.com, but also addressed to user2 at domain.com.  They BOTH 
get it delivered with the {spam} tag.  If just user2 at domain.com gets the 
email, then it gets stored.

Any thoughts on how to deal with this?

MTA: Sendmail (most up to date that yum update gives) on Centos 4.7