Converting mail from Exchange, padlock icon, $CSVersion

I am converting mail from Exchange to Notes using the Domino conversion tools. In the new mail files, each message in the Inbox and user folders has view icon 164 (an envelope overlayed by a padlock) in front of it. Messages in the sent view don’t have the icon.

I looked at the column code in the folders…it is governed by the following line (if CSisPrivate, the icon will appear):

CSisPrivate := @If(@IsUnavailable($PublicAccess) & @IsAvailable($CSVersion);“1”;“0”);

Sure enough, each of the mail documents has a $CSVersion field (and $CSFlags). Shouldn’t these only be there for calendar entries? Why is the conversion tool putting these fields into my emails? Is there anything wrong with just deleting these $CS fields (it does make the icon go away)?