Random Characters in rcvd=

I am having an issue with Kiwi syslog 7.1.0 we have a firewall logging to it then kiwi logs to a sql db.  When i try to run reports i get stopped.  I have found that there are a bunch of rcvd=A and other random characters in the rcvd= it takes me almost a month to go through each line and then manually delete the line that has the random character.  Is there a way to filter out the rcvd=A and other random characters.  Thank You in advanced for all your help.