Whitelisting half a site

[Derrick Georgiades]

I have had the issue of an email that is tagged as spam is delivered to
multiple recipients successfully if one recipient is whitelist.  Some of my
users want MailScanner scanning there incoming emails and some do not.
Because of this I have about 300 user addresses in my whitelist file.
IE:

To:     jdoe at mydomain.com       yes

This works except when a spam mail has multiple recipients for my domain.  I
know that there is no functionality to create two separate emails, but is
there a better way to whitelist?