The link created in /var/lib is spelled incorrectly which means the link target never receives any data.
lrwxrwxrwx 1 root root 31 Oct 7 09:09 spamassasin -> /var/mail-state/lib-spamassasin
drwxr-xr-x 3 debian-spamd debian-spamd 3 Oct 5 17:07 spamassassin
The link created in /var/lib is spelled incorrectly which means the link target never receives any data.