mailscanner caching and the cache cecksum

[ram]

MailScanner implements caching of Mails ( and does that very well ) 

How are these caches compared ?  Is there a checksum it generates?. If
yes can that checksum also be a extra header added in the mail ?


  Suppose I have a Spamassassin FN which gets detected after the mail
has been delivered , what I could do is look for all mails with the same
cache checksum header and delete them from all users mailbox immediately
( before they have seen the mail :-) and get another chance to
complain )


Thanks
Ram