Postfix emits this warning (ending up in /var/log/warn and triggering system
monitoring alerts):

  Jan 28 20:01:43 prod postfix/postfix-script[1780]: warning: group or other
writable: /etc/postfix/./ssl/cacerts

Here's that file and what it ultimately points to:

  $ ls -l /etc/postfix/ssl
  total 4
  lrwxrwxrwx 1 root root   15 Dec 22 13:13 cacerts -> ../../ssl/certs/
  drwxr-xr-x 2 root root 4096 May 17  2017 certs/

  $ ls -ld /etc/ssl/certs
  lrwxrwxrwx 1 root root 28 Oct 12 21:28 /etc/ssl/certs ->
/var/lib/ca-certificates/pem/

  $ ls -ld /var/lib/ca-certificates/pem
  dr-xr-xr-x 2 root root 28672 Nov 16 20:14 /var/lib/ca-certificates/pem/


Note that the file is actually a symbolic link, and the directory it ultimately
does point to is not group or world readable.

BUG: Postfix should not warn about the readability of symbolic links.