I am still getting messages that are getting past spamassassin. SpamAssassin is called from system procmail rules. Procmail provides an error that says program failed with an exit code of -25. A Google search reveals that many people are experiencing these and suggests a possible resource shortage.
These machines are short on disk space at this point so I am going to enlarge the virtual disks to see if this resolves the issue.
If anyone else has any information about this error, please e-mail nanook@eskimo.com.