How to Whitelist Using...

SpamAssassin:

Add the following entry to your user_prefs file, which is found in the
.spamassassin subdirectory on your web/mail server:

whitelist_from listserver@stagesource.org

Save the user_prefs file or move the updated copy to your .spamassassin subdirectory.
If you have no user_prefs file in this subdirectory, create one: 
http://spamassassin.taint.org/doc/Mail_SpamAssassin_Conf.html
http://www.cleanmymailbox.com/sa