On debian flavours there is no
/etc/mail/spamassassin/spamassassin-spamc.rc which all your symlinks
/etc/mail/spamassassin/spamassassin-spamc.rc is only installed on RH flavours.
That file contains
# send mail through spamassassin
Which is ok on debian flavours so I would suggest having VM create that file if its missing or simply not use that hard coded symlink.