For upgrading Spamassassin to 3.1.6-1    
Comment out the following entry in crontab 
0-59/10 * * * * /usr/local/lib/mailcheck/bin/mailcheck 
 
Now stop the service amavis by using commamd 
 /etc/init.d/amavis stop 
Check whether the older version of spammassassin is installed or not by using the    
following command:           
rpm -qa | grep -i spam
               if it enlists some older version installed then uninstall it using           
rpm -e command.
  
Install Spamassasin with rpm using            
             
 rpm -ivh spamassasin-3.1.6-1.i586.rpm
 rpm -ivh perl-Mail-SpamAssasin-3.1.6-1.i586.rpm
  
Start the service amavis using following command
/etc/init.d/amavis start
Uncomment  the following entry in crontab, which u have commented in step 1 
0-59/10 * * * * /usr/local/lib/mailcheck/bin/mailcheck 
  
Test spamassasin by sending a test mail.